Little trick I learned from a bus mechanic. Turn glow plugs on let them cycle once. Then turn key back to accessory for 15 seconds. Then fire her up. Works every time. He told me "some 7.3s are just hard startin sumbitches" they had 6 buses out of their whole fleet that just did that.
Exact issue I had with my 96 a few years ago, and exactly how I figured it out. I knew the truck was gonna need some TLC when I inspected/bought it with ~228K on odo. Still going strong!
Great informative vid what I did was bought a winch relay that had a bigger duty cycle than factory and it was $18 so far works great and should last longer I hope I didn't want to spend the $60+ if at all possible thanks
LOVE this model truck and engine !! The GP relay is really common. In my opinion they are like any other starter relay. They burn out with so many cycles. I believe glow plugs were meant to be changed every 100,000 as a rule of thumb. Very easy to change . If you can do a LS1 swap you can do glow plugs. the only thing to be careful with is the locking clips on the inside of the valve cover gasket. They get brittle from the heat. I normally left them attached to the vc gasket and disconnected the terminal at the glow plug and injector. Take care of this truck and it will out last YOU. I would love to have one just like it 😍
Thank you for the tip on the valve cover gasket. I'm not a mechanic by trade, I did collision repair body work for 20 years but didn't get into the mechanical side of cars until lately. I bought the truck with 162k miles on it and don't know much about its history so I'm going through it slowly and talking to local mechanics about the little things a 7.3 needs. I did my research on trucks before I got this one, the 7.3 seems to be known for running forever. :)
If you put a switch on the flow plug relay and switch them inside the cab they last a long time. I don’t use the glow plugs in the summer. Ford also triggers the glow plugs when you are going down the road and the voltage gets high.
I am going to try the sticksion treatment and check glow plug soliniod but I don't understand if it does start warm that would suggest it is working though?
@@JohnHynes_at_lookituplive If the motor is hot you don't need the glow plugs to turn on. I never had a problem starting this truck till I moved up here to a colder climate. That's when I figured out the glow plugs weren't turning on. :)
The sender to the glowplug relay sometimes keeps the glow plugs on too long and burns them out! So what I did is hook the sender wire to a push button on the dash to activate the relay. That way they don’t burn out by that stupid thermostatic sender that burned the glow plugs out. After a couple of sets of plugs , That was 20 years goo and the glow plugs are still working!... Manually!
ah we thought ya had some trouble starting when cold as in not starting when turned over. sometimes can get the block heaters that go in freeze out plug holes. saves from having the hard starts in cold.
It would turn over all morning until the batteries went dead because the glow plugs were never getting power. Sometimes it would start but would take several key cycles and smoke like a champ until it warmed up a bit. Now it starts up after one key cycle, all cylinders firing and very little smoke. So glad it wasn't the glow plugs. Glow plugs are an expensive fix. lol Thank you for watching. :)
Recently sorted out my 2000 7.3 hard/no start cold issue. Relay was bad, and used a test light and voltage gauge to test before hand. also had 1 battery that dropped to 105 CCA under load, so that also was hurting it. I heard somewhere(not sure of accuracy) that weak batteries won't allow the relay to activate the solenoid, so make ure you have 11V-12V constant, and no lower than 10V on the KOEO terminal of GPR. Only use a Ford Motorcraft relay. Same on glowplugs. Checking the glowplugs themselves for power is a PITA on an intercooled 7.3! LOL. Those harness plugs are old, and those heater hoses if original, will probably break or start leaking (mine did). Replaced with Motorcraft as well. They were due. Also don't replace the wrong solenoid by mistake, as my truck has two that look almost identical. GPR is the back one. the one in front is the air intake heater solenoid. Once you've sorted out everything with the glow plugs, here is something else. The HPOP. If you haven't flushed out that oil this year or in a long time, thoe 2 quarts of oil running in the HPOP reservoir and the heads is probably dirty and thick. Watch your dash oil pressure gauge when cranking. If it doesn't budge, until started, even after multiple cranks, it's either thick dirty oil in there, trying to fire the injectors, or the pump gears are worn. Fresh oil in there with some good additive (Archoil) will save your injectors too. A number of vids online how to easily flush this out. Don't frge your block heater is a pinch !
I have 2000 7.3 Ford f350 I have changed that relay you just did and my glow plugs but it starts better but still struggles to start any ideas what to look for next don't get me wrong it's definitely better but still hates the cold
When its cold around here (below 40 F) I run 2 cycles of the wait to start light before I try to start it. But if it's not turning over fast look at your battery cables. I had to make new battery cables for my truck because they were so corroded but after I installed new cables it turned over really fast. Hope this helps. Thanks for watching. :)
Your welcome I actually think your subscribed to my channel as well be for I changed the relay wich tested bad and put new glow plugs on it at 40 dagrees it would start taking forever to start as it got colder it take 45 minutes before it would start changing all that it takes about 9 minutes so its definitely better my 7.3 only has like 290,000 miles on it I'm thinking my next step is battery cable's my batteries are fairly new I see you live rv lifestyle as well stay warm thank you for this video awesome job on your content and thank you for responding back
i don't understand how your prob works with it being hook up to both positive and negative ... my light has only one lead so I see the hot on the big terminal and no power to the other big terminal but not sure how to check the 2 small terminal ... ya i have a card in my pocket that says I'm slow but not stupid and i had to put up with that condition for 64 year so bare with me pls ...
The easiest way to test to see if this is your problem is to turn you ignition on and cross the two large terminals with a wrench for about 20-30 seconds, then go and start your truck. If your truck fires up faster than normal you should get a new solenoid. :)
@@KoalityofLife I think the wiring was wrong, me and my dad read the Chilton book and the ignition side was the only one with fire to it so we bypassed it to a toggle switch to heat the glow plugs, I'll find out in the mornin when it's cold enough to see if it's gonna work
I have a 2001 7.3 with no relay, but it has Glow Plug Module. Tough to start in 40 degree weather. That isn't that cold. Any idea's how to test the Glow Plug Module.
40 degrees really isn't that cold, your truck shouldn't have a tough time starting. If it doesn't crank over fast check your battery connections. I don't have a way to check your glow plug module. :)
I changed the glow plugs and there’s nothing wrong with my relay but it still throws a fit for some reason, even today I had to wait for 2 minutes for the glow plugs to really do their thing and it was struggling to start. Could it maybe be because I didn’t buy oem glow plugs and offbrand auto lite ones from autozone?
I don't know about off brand glow plugs but when it gets down below freezing I will wait for the "wait to start" light to turn off and then cycle the ignition off and on again waiting for the light to turn off again before trying to start my truck. If it gets down into the single digits I will cycle it three times. I find that the motor fires a lot faster. :)
I know im late for the party but im trying to get an answer anywhere i can.. ive got power to the relay power to the constant key on small post. No power to the other big post. Ive gone through 4 relays and an oil temp sensor. anyone have any thoughts?
@@Oh9Shelby Sorry, assuming the problem you are having has to do with your 7.3 not starting because thats what this particular video is about. There is a relay for the glow plugs that goes out and will make it really hard to start your truck. :)
Thank you. Close ups would have been nice, I need to get some better camera equipment so I can see what I'm filming. Using an old GoPro I can't tell what I'm capturing so I have it set back a little ways but I'm hoping people can understand whats going on. Thanks for watching. :)
my 7.3 seems to be louder than the other 7.3s I have heard. Might just be me overthinking it, I haven't had any other diesel trucks so nothing to compare it to. It does seem a bit louder until it gets warmed up though. :)
@@KoalityofLife I have been looking at videos about rough running because of sticksion with fuel injectors and oil making them stick until oil is hot makes sense even to extreme the injectors start to wear then need replaced or shimmed so gape is not under 4mm
@@JohnHynes_at_lookituplive I don't know much about this, I have heard a bit about how Ford had some trucks that had injectors ran off the oil or oil pressure. My trucks injectors are electrical so I don't think oil or oil pressure has anything to do with it. I'm not a mechanic so don't quote me on this, just what i have heard. I'm trying to learn more about it. :)
@@KoalityofLife I went with the easiest but cost $180, and replaced glow plug module controller and the next morning started up with no issues. There are several videos with bad glow plug relay test but nothing if you have a controller module but one that was replaced and it worked
@@KoalityofLife of course! In all seriousness I used to work on an ambulance and we would spray everything from carb cleaner to hair spray to make those 7.3s fire up. My 7.3 in my personal truck always ran good. It’s all about proper maintenance.
@@fastfordman1965 I haven't had any problems with my truck other than regular maintenance, batterie terminals and battery cables have gone bad, a relay here and there, hoping it stays that way. Again thanks for watching. :)
Well, I bought the truck used and after fixing the neglected stuff I haven't had a problem with it, knock on wood. On a cold morning it starts right up after letting the glow plugs warm for about a min or two. Cant ask for much more from a 23 year old truck. Thanks for watching. :)
You need to be more in-depth in a close-up on what wires go where I have replaced a few glow plug relays and still seem to find having problems with the 73's in the cult I'm starting my 12 valve has an issue with starting in the cold also if it's not plugged in which it shouldn't we need more in-depth on your mechanic isms of how this actual glow plug relay works because we do not know the actual mechanic isms of it makes it a lot harder to understand yes we know that the light is supposed to stay on but how long is the light supposed to stay on and if there is no light that's a no-brainer that it's not getting power through to the other side what is their power coming into the side before it gets to the other side so that you have to be more inclusive and intrusive on your diagnosis to let other people know simplified measures to make this easier task than a difficult one there's really no schematic behind it I'm what you are showing
Nicely done, clear and simple testing procedures.
Little trick I learned from a bus mechanic. Turn glow plugs on let them cycle once. Then turn key back to accessory for 15 seconds. Then fire her up. Works every time. He told me "some 7.3s are just hard startin sumbitches" they had 6 buses out of their whole fleet that just did that.
I had tried that but the relay wasn't kicking on so the glow plugs never even turned on. Isn't a problem until winter comes around. lol :)
Exact issue I had with my 96 a few years ago, and exactly how I figured it out. I knew the truck was gonna need some TLC when I inspected/bought it with ~228K on odo. Still going strong!
Love my truck. Thanks for watching. :)
oh i for got to thank you for putting this clip out (nice job)
You're welcome. Thank you for watching. Feel free to share the video or tell friends about our channel. :)
Great informative vid what I did was bought a winch relay that had a bigger duty cycle than factory and it was $18 so far works great and should last longer I hope I didn't want to spend the $60+ if at all possible thanks
Glad you like the video, I would have never thought about the wench relay idea. Thank you for watching. :)
Thanks for the help!
Any time, thanks for watching. :)
Outstanding. Very succinct instructions....much appreciated.
You're very welcome, thanks for watching. )
Very good video descriptions of problem and how to fix. Great job buddy. Thank you
Thank you and your welcome. :)
Good video man! Thanks.
You're welcome. Feel free to share the video and help our channel grow. :)
Thanks
You're welcome. :)
Love your video….. I have a 2001 7.3 diesel but the transmission heats up and then start an oil leak any idea what could be the problem??
Thanks for watching. I have not heard of that problem before and unfortunately I would have to be there when it happened to be able to diagnose it.
Agree way to much but I'm getting old also but say same about my Harley
Thanks for watching :)
LOVE this model truck and engine !! The GP relay is really common. In my opinion they are like any other starter relay. They burn out with so many cycles. I believe glow plugs were meant to be changed every 100,000 as a rule of thumb. Very easy to change . If you can do a LS1 swap you can do glow plugs. the only thing to be careful with is the locking clips on the inside of the valve cover gasket. They get brittle from the heat. I normally left them attached to the vc gasket and disconnected the terminal at the glow plug and injector. Take care of this truck and it will out last YOU. I would love to have one just like it 😍
Thank you for the tip on the valve cover gasket. I'm not a mechanic by trade, I did collision repair body work for 20 years but didn't get into the mechanical side of cars until lately. I bought the truck with 162k miles on it and don't know much about its history so I'm going through it slowly and talking to local mechanics about the little things a 7.3 needs. I did my research on trucks before I got this one, the 7.3 seems to be known for running forever. :)
If you put a switch on the flow plug relay and switch them inside the cab they last a long time. I don’t use the glow plugs in the summer. Ford also triggers the glow plugs when you are going down the road and the voltage gets high.
Nice analysis. Concise and easy to understand. Do you have link to the tester?
I posted an amazon link to the Power Probe in the description. Thanks for watching. :)
Thanks, I added the link to my Amazon wish list.
@@qfdforme Thanks. :)
Thank you for sharing, very helpfull
You're very welcome. :)
I am going to try the sticksion treatment and check glow plug soliniod but I don't understand if it does start warm that would suggest it is working though?
@@JohnHynes_at_lookituplive If the motor is hot you don't need the glow plugs to turn on. I never had a problem starting this truck till I moved up here to a colder climate. That's when I figured out the glow plugs weren't turning on. :)
Ty it helped.
You're welcome. :)
The sender to the glowplug relay sometimes keeps the glow plugs on too long and burns them out!
So what I did is hook the sender wire to a push button on the dash to activate the relay. That way they don’t burn out by that stupid thermostatic sender that burned the glow plugs out. After a couple of sets of plugs ,
That was 20 years goo and the glow plugs are still working!...
Manually!
Thanks for saying something, I have never heard of that problem but will look into it. :)
ah we thought ya had some trouble starting when cold as in not starting when turned over. sometimes can get the block heaters that go in freeze out plug holes. saves from having the hard starts in cold.
It would turn over all morning until the batteries went dead because the glow plugs were never getting power. Sometimes it would start but would take several key cycles and smoke like a champ until it warmed up a bit. Now it starts up after one key cycle, all cylinders firing and very little smoke. So glad it wasn't the glow plugs. Glow plugs are an expensive fix. lol Thank you for watching. :)
Recently sorted out my 2000 7.3 hard/no start cold issue. Relay was bad, and used a test light and voltage gauge to test before hand. also had 1 battery that dropped to 105 CCA under load, so that also was hurting it. I heard somewhere(not sure of accuracy) that weak batteries won't allow the relay to activate the solenoid, so make ure you have 11V-12V constant, and no lower than 10V on the KOEO terminal of GPR. Only use a Ford Motorcraft relay. Same on glowplugs. Checking the glowplugs themselves for power is a PITA on an intercooled 7.3! LOL. Those harness plugs are old, and those heater hoses if original, will probably break or start leaking (mine did). Replaced with Motorcraft as well. They were due. Also don't replace the wrong solenoid by mistake, as my truck has two that look almost identical. GPR is the back one. the one in front is the air intake heater solenoid. Once you've sorted out everything with the glow plugs, here is something else. The HPOP. If you haven't flushed out that oil this year or in a long time, thoe 2 quarts of oil running in the HPOP reservoir and the heads is probably dirty and thick. Watch your dash oil pressure gauge when cranking. If it doesn't budge, until started, even after multiple cranks, it's either thick dirty oil in there, trying to fire the injectors, or the pump gears are worn. Fresh oil in there with some good additive (Archoil) will save your injectors too. A number of vids online how to easily flush this out. Don't frge your block heater is a pinch !
Very nice, thank you and thanks for watching. :)
I have 2000 7.3 Ford f350 I have changed that relay you just did and my glow plugs but it starts better but still struggles to start any ideas what to look for next don't get me wrong it's definitely better but still hates the cold
When its cold around here (below 40 F) I run 2 cycles of the wait to start light before I try to start it. But if it's not turning over fast look at your battery cables. I had to make new battery cables for my truck because they were so corroded but after I installed new cables it turned over really fast. Hope this helps.
Thanks for watching. :)
Your welcome I actually think your subscribed to my channel as well be for I changed the relay wich tested bad and put new glow plugs on it at 40 dagrees it would start taking forever to start as it got colder it take 45 minutes before it would start changing all that it takes about 9 minutes so its definitely better my 7.3 only has like 290,000 miles on it I'm thinking my next step is battery cable's my batteries are fairly new I see you live rv lifestyle as well stay warm thank you for this video awesome job on your content and thank you for responding back
@@rvoverland01 You're very welcome. :)
Thanks for the info. Btw you could be a double for Kevin Costner ☺️
I've been getting that a lot, looking like Kevin Costner, I don't see it but there must be something to it cause it keeps coming up. lol :)
You can make a fire under the engine with your lovely logs, that would warm up your glow plugs
That would warm up the whole truck lol. :)
i don't understand how your prob works with it being hook up to both positive and negative ... my light has only one lead so I see the hot on the big terminal and no power to the other big terminal but not sure how to check the 2 small terminal ... ya i have a card in my pocket that says I'm slow but not stupid and i had to put up with that condition for 64 year so bare with me pls ...
The easiest way to test to see if this is your problem is to turn you ignition on and cross the two large terminals with a wrench for about 20-30 seconds, then go and start your truck. If your truck fires up faster than normal you should get a new solenoid. :)
I have a 96 and I've replaced glowplugs, relays, ran a toggle switch for direct fire to the glow plugs and still won't start
I have no idea where to go from there unless I was there to test and diagnose the truck. :)
@@KoalityofLife I think the wiring was wrong, me and my dad read the Chilton book and the ignition side was the only one with fire to it so we bypassed it to a toggle switch to heat the glow plugs, I'll find out in the mornin when it's cold enough to see if it's gonna work
@@nonprooutdoorsandmore2303 Nice, let me know if you get it running. :)
Thankfully the bypass works. No more crankin and waitin and battery drainin
@@nonprooutdoorsandmore2303 Very nice. :)
I have a 2001 7.3 with no relay, but it has Glow Plug Module. Tough to start in 40 degree weather. That isn't that cold. Any idea's how to test the Glow Plug Module.
40 degrees really isn't that cold, your truck shouldn't have a tough time starting. If it doesn't crank over fast check your battery connections. I don't have a way to check your glow plug module. :)
@@KoalityofLife ok. Thank you
i had a buddy who had a diesel and his fuel went to gel it was so cold.
I have heard of that happening but only if you don't run your diesel enough to put new diesel in it during the cold months. :)
I changed the glow plugs and there’s nothing wrong with my relay but it still throws a fit for some reason, even today I had to wait for 2 minutes for the glow plugs to really do their thing and it was struggling to start. Could it maybe be because I didn’t buy oem glow plugs and offbrand auto lite ones from autozone?
I don't know about off brand glow plugs but when it gets down below freezing I will wait for the "wait to start" light to turn off and then cycle the ignition off and on again waiting for the light to turn off again before trying to start my truck. If it gets down into the single digits I will cycle it three times. I find that the motor fires a lot faster. :)
What year is your truck?
Thats a 1997 Ford F-250HD
I know im late for the party but im trying to get an answer anywhere i can.. ive got power to the relay power to the constant key on small post. No power to the other big post. Ive gone through 4 relays and an oil temp sensor. anyone have any thoughts?
Have you replaced the solenoid? :)
@@KoalityofLife solenoid? what are we talking about?
@@Oh9Shelby Sorry, assuming the problem you are having has to do with your 7.3 not starting because thats what this particular video is about. There is a relay for the glow plugs that goes out and will make it really hard to start your truck. :)
Nicely explain. Thank you. Need close ups to make it better.
Thank you. Close ups would have been nice, I need to get some better camera equipment so I can see what I'm filming. Using an old GoPro I can't tell what I'm capturing so I have it set back a little ways but I'm hoping people can understand whats going on. Thanks for watching. :)
I am having cold start issues, and question would your engine ring rough till warmed up?
my 7.3 seems to be louder than the other 7.3s I have heard. Might just be me overthinking it, I haven't had any other diesel trucks so nothing to compare it to. It does seem a bit louder until it gets warmed up though. :)
@@KoalityofLife I have been looking at videos about rough running because of sticksion with fuel injectors and oil making them stick until oil is hot makes sense even to extreme the injectors start to wear then need replaced or shimmed so gape is not under 4mm
@@JohnHynes_at_lookituplive I don't know much about this, I have heard a bit about how Ford had some trucks that had injectors ran off the oil or oil pressure. My trucks injectors are electrical so I don't think oil or oil pressure has anything to do with it. I'm not a mechanic so don't quote me on this, just what i have heard. I'm trying to learn more about it. :)
@@KoalityofLife I went with the easiest but cost $180, and replaced glow plug module controller and the next morning started up with no issues. There are several videos with bad glow plug relay test but nothing if you have a controller module but one that was replaced and it worked
@@JohnHynes_at_lookituplive Good deal, Thats not to expensive for a fix. :)
Nothing a little Cosby in a can can’t fix. Don’t forget to pin it into the danger zone with full ketchup. 👌
Thanks for watching. :)
@@KoalityofLife of course! In all seriousness I used to work on an ambulance and we would spray everything from carb cleaner to hair spray to make those 7.3s fire up. My 7.3 in my personal truck always ran good. It’s all about proper maintenance.
@@fastfordman1965 I haven't had any problems with my truck other than regular maintenance, batterie terminals and battery cables have gone bad, a relay here and there, hoping it stays that way. Again thanks for watching. :)
I find it funny that when a Powerstroke takes an hour to start where I live the 6.2 Detroit next to it starts in a matter of a few minutes 😂
Well, I bought the truck used and after fixing the neglected stuff I haven't had a problem with it, knock on wood. On a cold morning it starts right up after letting the glow plugs warm for about a min or two. Cant ask for much more from a 23 year old truck. Thanks for watching. :)
@@KoalityofLife Yeah they can sure be great trucks!
You need to be more in-depth in a close-up on what wires go where I have replaced a few glow plug relays and still seem to find having problems with the 73's in the cult I'm starting my 12 valve has an issue with starting in the cold also if it's not plugged in which it shouldn't we need more in-depth on your mechanic isms of how this actual glow plug relay works because we do not know the actual mechanic isms of it makes it a lot harder to understand yes we know that the light is supposed to stay on but how long is the light supposed to stay on and if there is no light that's a no-brainer that it's not getting power through to the other side what is their power coming into the side before it gets to the other side so that you have to be more inclusive and intrusive on your diagnosis to let other people know simplified measures to make this easier task than a difficult one there's really no schematic behind it I'm what you are showing
Sorry about the confusion. If I get a chance I will put out another video explaining how the relay works in this application. Thanks for watching. :)