Old school instrument guy here. When you first turned the gauge on and it rose to well past "full" it looked like a classic voltage regulator failure. In this case, you're lucky, it was a simple fix but don't forget the little 5 volt regulator box behind the gauges. It's just a thermal bi-metal device and when the contacts points inside burn out it's curtains for the gauges. The gauges themselves are also a thermal bi-metal system which is such a simple mechanism that, of themselves, will never fail. If the gauge fails it will only fail because of external problems like wiring or the voltage regulator. If you ever see the gauges simultaneously rise to full quickly, turn off your ignition immediately because a stuck regulator will burn the gauges out in seconds. Anyway, just don't ever forget that little box behind the gauges. Hope you don't mind my two cents. 🙂
Ok, if you got a pump to siphon with but, the car only has 5" of ground clearance so you can't just use a hose and the ol' suck it out by gravity. The rubber gaiter only takes a couple of minutes to remove.
Same problem here. My tank is so full I can see the gas when I take the cap off yet gage is at E. My 78 B has small black hose with a clamp attached to the sending unit unlike yours. Whats the procedure for this? First time MGB owner here trying to do the little things myself. Thanks in advance!
My MGB is a 1973 (chrome bumper) model. When they went to the 1975 -1980 model (rubber bumper) they did away with the 'bung' on the tank for the fuel pick-up and put the pick-up on the sending unit. That hose is for the fuel and goes to the fuel pump inlet. If you want to learn more about your MG here is a free forum called THE MG EXPERIENCE. It has thousands of MG owners who can help you when you need advice about your MG. It's free to join. www.mgexp.com/forum/mgb-and-gt-forum.1/what-did-you-do-with-your-mgb-today.1940738.4088827/page-1258#msg-4088827
Perhaps that sending unit also has another application in a plastic tank somewhere where it would need a ground wire as it could not be grounded as our host indicated.
Very nice job with a sense of humor AND an explanation of how it should work. Thanks for your help...just did mine tonight.
Old school instrument guy here. When you first turned the gauge on and it rose to well past "full" it looked like a classic voltage regulator failure. In this case, you're lucky, it was a simple fix but don't forget the little 5 volt regulator box behind the gauges. It's just a thermal bi-metal device and when the contacts points inside burn out it's curtains for the gauges.
The gauges themselves are also a thermal bi-metal system which is such a simple mechanism that, of themselves, will never fail.
If the gauge fails it will only fail because of external problems like wiring or the voltage regulator.
If you ever see the gauges simultaneously rise to full quickly, turn off your ignition immediately because a stuck regulator will burn the gauges out in seconds. Anyway, just don't ever forget that little box behind the gauges.
Hope you don't mind my two cents. 🙂
Many thanks for taking the time to show how it’s done. Much appreciated.
Thanks for this video - you just saved me a lot of time and effort!
Thanks for the tips, I also liked your short film Mr Blowhard, from JC in down-under Australia 👍👍👍
Thanks for the detail about the sending unit being free moving, I guess saving old parts comes in handy, especially with cheaper made in china parts!
You're welcome.
Thanks for help. I forgot about the "little nitch" until I saw this. Have 74 MGB
Glad to have helped.
Great video - good explanation and well filmed (sharp resolution).
Thanks.
thank you sir
Just stick a pipe in the tank and siphon out the fuel. It saves time messing around with the rubber gaiter.
Ok, if you got a pump to siphon with but, the car only has 5" of ground clearance so you can't just use a hose and the ol' suck it out by gravity. The rubber gaiter only takes a couple of minutes to remove.
Same problem here. My tank is so full I can see the gas when I take the cap off yet gage is at E. My 78 B has small black hose with a clamp attached to the sending unit unlike yours. Whats the procedure for this? First time MGB owner here trying to do the little things myself. Thanks in advance!
My MGB is a 1973 (chrome bumper) model. When they went to the 1975 -1980 model (rubber bumper) they did away with the 'bung' on the tank for the fuel pick-up and put the pick-up on the sending unit. That hose is for the fuel and goes to the fuel pump inlet. If you want to learn more about your MG here is a free forum called THE MG EXPERIENCE. It has thousands of MG owners who can help you when you need advice about your MG. It's free to join. www.mgexp.com/forum/mgb-and-gt-forum.1/what-did-you-do-with-your-mgb-today.1940738.4088827/page-1258#msg-4088827
I've got a '76 and its exactly like the one in the video. Separate fuel line inlet and only one wire from guage.
You didnt ground the sender
The sending unit is grounded thru the tank.
@mike gellner If you look closer, it's still grounded thru the face of the sending unit.other wise it wouldn't work.
@mike gellner If you look closer you will notice that it is grounded thru the face of the sending unit other wise it would not work at all.
Perhaps that sending unit also has another application in a plastic tank somewhere where it would need a ground wire as it could not be grounded as our host indicated.