Another great video. Avionics (I know it’s not really) scare the poop out of me. Sent the torn seat off to a chap in Wells for repair. When George took the seat out he found a fair bit of mold after the winter. We will have to come up with a plan for next year 🤷🏻♂️
I always knew my degree in electronic engineering would come in handy one day....let me know how the seat repair goes. I used to keep a box of water absorbing crystals in my car over winter.Mike
Good luck and great work! I had to do something similar to my D-Jet 1973 450 SL. Make sure to check the points in the distributor, as that is the "signal" that the control module receives.
Thanks for your comment. Good point. I may take the distributor off my 450SL parts car to familiarise myself with the set up. My next challenge is to figure out how the 'neutral safety switch' wiring interfaces with the starter motor...at present turning the key to crank position doesn't do anything. Mike
Thanks Mike. My fitter believes he has solved the problem now. The ICV is new but there is an electronic sensor on it that might not be receiving the correct signals from the ECU, which looks like it has been tampered with. My adjusting the throttle manually, he has obtained a smooth tickover after warm up of 500 -750rpm. Do you reckon I should have the ECU tested / replaced or is that expensive? In fact the engine runs fine now, so I might just leave it for now. Any comments would be much appreciated.
That is great news! My own view is that "If it aint broke dont fix it" so for the moment I would drive the car and see how it settles in. The ECU's are often blamed for faults but are rarely the culprit. It is expensive getting them tested...and there are not that many places that have the capacity to do so. What part of the country are you in? Mike
Mike can you tell me where your getting your new ballast resistors and screws and where you goto to determine their part number. Also the .4 is markered buy what is the size of the silver ballast resistor. This video is a massive help. please and thank you JoeB
Hi - the source and part numbers are usually given at the end of each video - at 17.55 in this particular video. I got the ballast resistors from eBay. Mike
I tend to agree. I am based in Hertfordshire. Next job is to have the seats re-upholstered. I have the replacement covers from California USA. Do you fancy quoting for the labour or is there someone good that you could recommend within 100 miles?
Hi - trimming is not something I would get involved in on someone else's car - best left to the professionals! I am based in Bristol and there are a couple of trimmers round here that I could recommend. In the first instance try a google search for "automotive trimmers hertfordshire" try and find someone that has done an old merc before as there are a few tricks....as you will see in the videos below.. th-cam.com/video/WZoJ2FBqXIQ/w-d-xo.html th-cam.com/video/ejwYa5QwNK4/w-d-xo.html Mike
Hi - do you mean where do the wires connect or do you mean what signal do they carry? At 15.34 in the video, I show where they connect. The exact ignition control module wiring depends what make model and year car do you have. If you send an email to m_scott65@hotmail.com I can send you a wiring diagram. Mike
Thanks Mike. I always enjoy your videos as I have a 300SL 1989 that is almost restored but the engine fails to idle. It revs and runs very sweet if throttle is used. My fitter has replaced the idle control valve (was missing and had a primitive LPG bolt doing the job before this), the coil, plugs, plug leads, distributor , fuel filter and fuel distributor. Do you think we should replace the ballast resisitors or do you have any other ideas? We think the problem must be electronic. Regards Nick.
Just a thought, but what happens when you disconnect the idle control valve - does the car idle albeit with high revs? Did he replace this unit with a new one or a 2nd hand one? Mike
Hmmm. Can you send me a photo of the idle air valve connected to the car...with the air box removed so I can see the rubber hoses and vacuum lines. m_scott65@hotmail.com Have you done a vacuum leak smoke test? I'm not an expert on the m103 engine in the 300SL. I know some of the later models like the 560SL had an idle air control module located behind the glove box....not sure about your car but maybe a call to Mercedes Parts dept or the SL Shop would confirm. Let me know how you get on. Mike @@HarpendenMillAutocare
Hello, congratulations on the demo videos! I wanted to know if you can help me with the repair of a BOSH 0227 0510 17 ignition control unit for a 1971 Mecedes C107. I can't find a Motorola SP2522 7239 transistor. Do you have suggestions? Thank you Luca
Hi - sorry to read you are having problems sourcing a Motorola transistor to repair you ignition control module. These transistors were often used in radios so you could try emailing Graham at radiocruncher.com. There is a guy on eBay who repairs mercedes ECU's and other modules. His eBay name is ecut79 or type in item number 355394603335. It is also worth checking ebay for people who are breaking SLC;s for example ebay item 285696750262. Good luck Mike
These resistors are generally colour coded and have the ohm value stamped on the side- do you still have the old resistors? What model engine does car have (eg M110?) and what year is it? Mike
Great explenation and instructions, but make sure to clearly show the way that the wires from the ignition module and the ballast resistors go to the coil an connecting block (maybe in the next video?). If you find any problems with vaccuum leaks then make sure to change out the injector seal on all 6 of the injectors, they consist of 2 seals, 116 078 04 73 and 116 078 00 73, and make sure that you've got the right fuel pressure, should be between 2.0 and 2.2 bar. Kind regards, Martin
Thanks for your comments and your good advice. Just finished fixing the wiring and will be sure to clearly show how everything connects up in next video. It is quite different on this car than on my later 1976 280SL. At present nothing happens when key is turned to crank so I am ploughing through wiring diagram and trying to find the link between the neutral lock out switch on the transmission and the starter solenoid. It is always a bit trickier when the car arrives in bits and your not sure whether it has the correct engine or loom etc....Mike
@@MikesMercsandothercars yes it's always a headache to work on a car that somebody else also has tinkered with. I've got a similar engine in my W116 S-class, a M110 with D'jetronic '73, I could send you a video of how the cables at my connection block are connected on the starter motor side if it helps
@@MetaldetectingFriesland I assume your car is an auto? The car I am working on was originally a manual and they have put an auto box in there. When you turn the ignition key on your car to the ON position (eg before you actually crank the car, does your fuel pump switch on for 3 seconds? From memory, the fuel pump on K jetronic cars only primes when the starter motor engages. Also....I believe there should be a blue wire connected to the 'air mass flow sensor switch on the top right of the engine block. This switch tells the fuel pump whether or not the engine is running. No engine running should = no fuel pump on. Does you car have this and if so, where does this wire go (eg through the firewall?) Thanks Mike
@@MikesMercsandothercars yes mine indeed is an original automatic car, and yes if I turn on the ignition on the 2nd part the fuel pump engages for 3 seconds. All the wires from the sensors go directly into the engine wiring harness
@@MetaldetectingFriesland Jeez that was a quick reply. I think I have to crawl under the car and start testing the electrical contacts on the 'neutral safety switch' on my parts car and the project car. Out of interest: 1. If you turn you engine off when it is in drive...what happens when you try and crank it. I am assuming that it will be as dead as a doornail. 2. Does the engine have to be running for your reverse lights to come on....or will these lights come on when the key is in the ignition in the ON position? Thanks for you help. Mike
Hello Mike, how can i check my ignition control module is working properly. I make the mistake to recharge my battery with the minus and positive cable screwed to the battery. Since then i have some issue in starting the car a 1973 450 sl. Thx for your feed back. Cheers.
Hi - the easiest way is to swap the unit for a known good unit and see if the issue goes away....but the correct unit for a 1973 may be difficult to find. Where are you based? Mike
@@NicolasdeBreteuil Quel dommage, if your were closer, I would suggest swapping the unit from the car I am currently working on. Another alternative could be to bypass the ignition control module using the Petronix electronic ignition: www.benzworld.org/threads/pertronix-install-with-and-without-switchgear.1714668/ Mike
Hi John, the safety restraint system light generally comes on if you move the seat backwards or forwards and knock the connection which is often a yellow harness. My car is too old to have that system so I’m not sure of the exact set up on your car. Failing that, you can often turn that light off using a scanner. I have a scanner that will probably do the job. Mike
Hello, thank you for the video advice, I have a 1973 450SL that I have been restoring, I got to the point where I have tried to start it, No spark and now no power to the fuel pump. From what I gather the ballasts could be effecting the operation of both problems. Being in Canada the parts are pretty difficult to get, amazon seems to be the only solution, one question is I notice the parts numbers on the ballasts that you installed are different, why is that. Ronald
Hi - does your car turn over? Eg is there power to the starter motor? Not sure I understand your comment about part number - do you mean the part numbers are different from your car? Mike
@@MikesMercsandothercars ballasts one is 4ohms other is 6ohms... car turns over like crazy, no spark and fuel pump not working,(was working previuosly)
The ballast resistors shown in the video are correct for that car and they should be different values. Assuming there is no voltage at the fuel pump, the first place I would look is at the fuel pump relay. Take the relay out and crank the engine and see if you get any voltage where the relay plugs in. Have a look at the video I did on first turning over the car. No spark - first thing I would check is that you have connected the coil to the distributor….the amount of times I have forgotten to reattach that central lead! Next I would be checking that you are getting voltage to and from coil….and finally you could check voltage at resistors. Good luck. Mike
Another great video, thanks Mike. On my 450SLC the ballast resistors get really hot with the ignition turned on but engine not running. Is that normal? Until this video I assumed that the ballast resistors were parts for life and would never need replacing but maybe mine do
Ballast resistors lower and regulate the voltage by turning that voltage into hear so they do get hot. Obviously as the car is moving, air will cool them down. I suspect that over time the insulation starts to deteriorate which is why they get super hot. If the resistance was higher than it should be because of corrosion etc, the resistors would get hotter than they should....but you would tend to notice this in the running/idling of your car as the spark would be less powerful. For the sake of £50 and a couple of screws, I would change them....and let me know if it makes any difference to the running/starting of your car...and the temperature of the resistors. Last but not least....what year is your car and have you got the correct coil on it? Mike
@@MikesMercsandothercars Thanks Mike. Mine is a 1974 car and the coil is blue. it runs fine and the resistors are not hot with the car running even if stationary but as you say for the cost of new ballast resistors i will replace them. In checking the coil colour I’ve also just noticed that there is a condenser or suppressor (small tube thing) attached to the bracket of the coil but its cable is not attached anywhere. It isn’t’t on the wiring diagram but I have no idea whether that is significant to anything
@@jonnybigpotato4263 Hmmm - once I get my car wired up correctly, I will be interested to do a temp test on the resistors when the ignition is switched ON but car not running. Blue coil is correct. On my 1974 450SL there was a small brass fitting on one of the plugs (you can see it at time code 4.21 in the video) This is a special port/plug for connecting a D Jetronic test probe to things like Dwell angle etc. Maybe that is what you are referring to? Mike
And thanks for the suggestion but no that round thing is different I have the one you refer to as well. The one I was asking about looks like what I had on a MK1 escort years ago and was described as a suppressor supposedly to stop the coil interfering with the radio. Maybe that is what this thing is too although it isn’t wired up and the radio is fine. It doesn’t seem to be doing any harm so best left as is for now
Thanks for your comment. Yes they are very similar. On the old mercs, the resistors are 0.6 ohm and 0.4 ohm. The 0.4 is by passed during cranking to give a better cold start spark. I think the old transits used much higher resistors like 1.6 ohm. Mike
Just looked back at that video and added chapters to make it easier to skip to parts that might be relevant. Did you have a problem with your ballast resistors? Mike
Another great video. Avionics (I know it’s not really) scare the poop out of me.
Sent the torn seat off to a chap in Wells for repair. When George took the seat out he found a fair bit of mold after the winter. We will have to come up with a plan for next year 🤷🏻♂️
I always knew my degree in electronic engineering would come in handy one day....let me know how the seat repair goes. I used to keep a box of water absorbing crystals in my car over winter.Mike
Good luck and great work! I had to do something similar to my D-Jet 1973 450 SL.
Make sure to check the points in the distributor, as that is the "signal" that the control module receives.
Thanks for your comment. Good point. I may take the distributor off my 450SL parts car to familiarise myself with the set up. My next challenge is to figure out how the 'neutral safety switch' wiring interfaces with the starter motor...at present turning the key to crank position doesn't do anything. Mike
Very well explained thank you
Thanks - those pesky ballast resistors can causes a whole host of problems.
Thanks Mike. My fitter believes he has solved the problem now. The ICV is new but there is an electronic sensor on it that might not be receiving the correct signals from the ECU, which looks like it has been tampered with. My adjusting the throttle manually, he has obtained a smooth tickover after warm up of 500 -750rpm. Do you reckon I should have the ECU tested / replaced or is that expensive? In fact the engine runs fine now, so I might just leave it for now. Any comments would be much appreciated.
That is great news! My own view is that "If it aint broke dont fix it" so for the moment I would drive the car and see how it settles in. The ECU's are often blamed for faults but are rarely the culprit. It is expensive getting them tested...and there are not that many places that have the capacity to do so. What part of the country are you in?
Mike
Mike can you tell me where your getting your new ballast resistors and screws and where you goto to determine their part number. Also the .4 is markered buy what is the size of the silver ballast resistor. This video is a massive help. please and thank you JoeB
Hi - the source and part numbers are usually given at the end of each video - at 17.55 in this particular video. I got the ballast resistors from eBay. Mike
I tend to agree. I am based in Hertfordshire. Next job is to have the seats re-upholstered. I have the replacement covers from California USA. Do you fancy quoting for the labour or is there someone good that you could recommend within 100 miles?
Hi - trimming is not something I would get involved in on someone else's car - best left to the professionals! I am based in Bristol and there are a couple of trimmers round here that I could recommend. In the first instance try a google search for "automotive trimmers hertfordshire" try and find someone that has done an old merc before as there are a few tricks....as you will see in the videos below..
th-cam.com/video/WZoJ2FBqXIQ/w-d-xo.html
th-cam.com/video/ejwYa5QwNK4/w-d-xo.html
Mike
Hey man I have a question, what are the wires coming from the ignition box brown, black,red, green? Any information would be appreciated
Hi - do you mean where do the wires connect or do you mean what signal do they carry?
At 15.34 in the video, I show where they connect.
The exact ignition control module wiring depends what make model and year car do you have. If you send an email to m_scott65@hotmail.com I can send you a wiring diagram.
Mike
Thanks Mike. I always enjoy your videos as I have a 300SL 1989 that is almost restored but the engine fails to idle. It revs and runs very sweet if throttle is used. My fitter has replaced the idle control valve (was missing and had a primitive LPG bolt doing the job before this), the coil, plugs, plug leads, distributor , fuel filter and fuel distributor. Do you think we should replace the ballast resisitors or do you have any other ideas? We think the problem must be electronic. Regards Nick.
Sorry to hear you are having problems - where are you based? I doubt whether the ballast resitors would have a bearing on this issue. Mike
Just a thought, but what happens when you disconnect the idle control valve - does the car idle albeit with high revs? Did he replace this unit with a new one or a 2nd hand one? Mike
@@MikesMercsandothercars
Hi Mike,
Idle control valve is new and when disconnected the problem still exist.
Thank You
Hmmm. Can you send me a photo of the idle air valve connected to the car...with the air box removed so I can see the rubber hoses and vacuum lines. m_scott65@hotmail.com
Have you done a vacuum leak smoke test?
I'm not an expert on the m103 engine in the 300SL. I know some of the later models like the 560SL had an idle air control module located behind the glove box....not sure about your car but maybe a call to Mercedes Parts dept or the SL Shop would confirm.
Let me know how you get on.
Mike @@HarpendenMillAutocare
Hello, congratulations on the demo videos!
I wanted to know if you can help me with the repair of a BOSH 0227 0510 17 ignition control unit for a 1971 Mecedes C107.
I can't find a Motorola SP2522 7239 transistor.
Do you have suggestions?
Thank you
Luca
Hi - sorry to read you are having problems sourcing a Motorola transistor to repair you ignition control module. These transistors were often used in radios so you could try emailing Graham at radiocruncher.com. There is a guy on eBay who repairs mercedes ECU's and other modules. His eBay name is ecut79 or type in item number 355394603335. It is also worth checking ebay for people who are breaking SLC;s for example ebay item 285696750262. Good luck Mike
@@MikesMercsandothercars Thank you very much for your suggestions!
mike will these ballast resistor sizes fit a 1976 280S?
These resistors are generally colour coded and have the ohm value stamped on the side- do you still have the old resistors? What model engine does car have (eg M110?) and what year is it? Mike
Great explenation and instructions, but make sure to clearly show the way that the wires from the ignition module and the ballast resistors go to the coil an connecting block (maybe in the next video?). If you find any problems with vaccuum leaks then make sure to change out the injector seal on all 6 of the injectors, they consist of 2 seals, 116 078 04 73 and 116 078 00 73, and make sure that you've got the right fuel pressure, should be between 2.0 and 2.2 bar.
Kind regards, Martin
Thanks for your comments and your good advice. Just finished fixing the wiring and will be sure to clearly show how everything connects up in next video. It is quite different on this car than on my later 1976 280SL. At present nothing happens when key is turned to crank so I am ploughing through wiring diagram and trying to find the link between the neutral lock out switch on the transmission and the starter solenoid. It is always a bit trickier when the car arrives in bits and your not sure whether it has the correct engine or loom etc....Mike
@@MikesMercsandothercars yes it's always a headache to work on a car that somebody else also has tinkered with. I've got a similar engine in my W116 S-class, a M110 with D'jetronic '73, I could send you a video of how the cables at my connection block are connected on the starter motor side if it helps
@@MetaldetectingFriesland I assume your car is an auto? The car I am working on was originally a manual and they have put an auto box in there.
When you turn the ignition key on your car to the ON position (eg before you actually crank the car, does your fuel pump switch on for 3 seconds?
From memory, the fuel pump on K jetronic cars only primes when the starter motor engages.
Also....I believe there should be a blue wire connected to the 'air mass flow sensor switch on the top right of the engine block. This switch tells the fuel pump whether or not the engine is running. No engine running should = no fuel pump on. Does you car have this and if so, where does this wire go (eg through the firewall?)
Thanks
Mike
@@MikesMercsandothercars yes mine indeed is an original automatic car, and yes if I turn on the ignition on the 2nd part the fuel pump engages for 3 seconds. All the wires from the sensors go directly into the engine wiring harness
@@MetaldetectingFriesland Jeez that was a quick reply. I think I have to crawl under the car and start testing the electrical contacts on the 'neutral safety switch' on my parts car and the project car. Out of interest:
1. If you turn you engine off when it is in drive...what happens when you try and crank it. I am assuming that it will be as dead as a doornail.
2. Does the engine have to be running for your reverse lights to come on....or will these lights come on when the key is in the ignition in the ON position?
Thanks for you help.
Mike
Hello Mike, how can i check my ignition control module is working properly. I make the mistake to recharge my battery with the minus and positive cable screwed to the battery. Since then i have some issue in starting the car a 1973 450 sl. Thx for your feed back. Cheers.
Hi - the easiest way is to swap the unit for a known good unit and see if the issue goes away....but the correct unit for a 1973 may be difficult to find. Where are you based? Mike
@@MikesMercsandothercars in France
@@NicolasdeBreteuil Quel dommage, if your were closer, I would suggest swapping the unit from the car I am currently working on. Another alternative could be to bypass the ignition control module using the Petronix electronic ignition:
www.benzworld.org/threads/pertronix-install-with-and-without-switchgear.1714668/
Mike
Mike….. George says the SRS light is on. Is this a problem or is there an easy fix?
I forgot to add that it was after the flat battery. So I imagine there will be a reset somewhere 🤷🏻♂️
Hi John, the safety restraint system light generally comes on if you move the seat backwards or forwards and knock the connection which is often a yellow harness. My car is too old to have that system so I’m not sure of the exact set up on your car. Failing that, you can often turn that light off using a scanner. I have a scanner that will probably do the job. Mike
@@MikesMercsandothercars thank you 🙏. I’ll pass that on to George. Also the passenger seat is out, so maybe could also be the cause.
Hello, thank you for the video advice, I have a 1973 450SL that I have been restoring, I got to the point where I have tried to start it, No spark and now no power to the fuel pump. From what I gather the ballasts could be effecting the operation of both problems. Being in Canada the parts are pretty difficult to get, amazon seems to be the only solution, one question is I notice the parts numbers on the ballasts that you installed are different, why is that. Ronald
Hi - does your car turn over? Eg is there power to the starter motor?
Not sure I understand your comment about part number - do you mean the part numbers are different from your car?
Mike
@@MikesMercsandothercars ballasts one is 4ohms other is 6ohms... car turns over like crazy, no spark and fuel pump not working,(was working previuosly)
The ballast resistors shown in the video are correct for that car and they should be different values.
Assuming there is no voltage at the fuel pump, the first place I would look is at the fuel pump relay. Take the relay out and crank the engine and see if you get any voltage where the relay plugs in. Have a look at the video I did on first turning over the car.
No spark - first thing I would check is that you have connected the coil to the distributor….the amount of times I have forgotten to reattach that central lead! Next I would be checking that you are getting voltage to and from coil….and finally you could check voltage at resistors.
Good luck. Mike
Another great video, thanks Mike. On my 450SLC the ballast resistors get really hot with the ignition turned on but engine not running. Is that normal? Until this video I assumed that the ballast resistors were parts for life and would never need replacing but maybe mine do
Ballast resistors lower and regulate the voltage by turning that voltage into hear so they do get hot. Obviously as the car is moving, air will cool them down. I suspect that over time the insulation starts to deteriorate which is why they get super hot. If the resistance was higher than it should be because of corrosion etc, the resistors would get hotter than they should....but you would tend to notice this in the running/idling of your car as the spark would be less powerful. For the sake of £50 and a couple of screws, I would change them....and let me know if it makes any difference to the running/starting of your car...and the temperature of the resistors. Last but not least....what year is your car and have you got the correct coil on it? Mike
@@MikesMercsandothercars Thanks Mike. Mine is a 1974 car and the coil is blue. it runs fine and the resistors are not hot with the car running even if stationary but as you say for the cost of new ballast resistors i will replace them. In checking the coil colour I’ve also just noticed that there is a condenser or suppressor (small tube thing) attached to the bracket of the coil but its cable is not attached anywhere. It isn’t’t on the wiring diagram but I have no idea whether that is significant to anything
@@jonnybigpotato4263 Hmmm - once I get my car wired up correctly, I will be interested to do a temp test on the resistors when the ignition is switched ON but car not running.
Blue coil is correct.
On my 1974 450SL there was a small brass fitting on one of the plugs (you can see it at time code 4.21 in the video) This is a special port/plug for connecting a D Jetronic test probe to things like Dwell angle etc. Maybe that is what you are referring to? Mike
Saw on your latest video that yours get hot too! Good to know
And thanks for the suggestion but no that round thing is different I have the one you refer to as well. The one I was asking about looks like what I had on a MK1 escort years ago and was described as a suppressor supposedly to stop the coil interfering with the radio. Maybe that is what this thing is too although it isn’t wired up and the radio is fine. It doesn’t seem to be doing any harm so best left as is for now
That look same as Ford Transit ballasts in the 80s & 90s etc.
Thanks for your comment. Yes they are very similar. On the old mercs, the resistors are 0.6 ohm and 0.4 ohm. The 0.4 is by passed during cranking to give a better cold start spark. I think the old transits used much higher resistors like 1.6 ohm. Mike
dude you talk too much
Just looked back at that video and added chapters to make it easier to skip to parts that might be relevant. Did you have a problem with your ballast resistors? Mike