Ignition relay 78MGB

[Lou A]

Can anyone tell me where the ignition relay is located on a 78 MGB? I can
see it in the schematics but I have no clue of its actual location in the car.
Lou A

[KimMG]

There are two relays, one on either side of fuse box. If original, they look like little round cans. If they have been replaced, they maybe cubed shape. The ignition relay has a white wire going to it and the starter relay has a white/red wire going to it.

Replacement relays are available at most autoparts stores for less than five dollars. Just ask for a generic 30amp Bosch style relay.

Are you having any problems with the relay? Or a particular circuit?

[Lou A]

KimMG,

Thanks for the reply. I was trying to fix a run on problem with my 78MGB. I've owned the car for 23 years and it has always run on after I turn off the ignition. I read on another forum that moving the white/brown wire (that goes to the distributor) from the fuse box and joining it to the same terminal with the white wire on the igntion relay would fix the run on. I bought some male and female disconnect plugs and with some wire I made a connector that had one female end and two male ends. The female end was plugged into the white wire terminal on the ignition relay, one male end plugged into the white/brown wire from the fuse box and the other male end was plugged into the white igntion relay wire. I'm happy to report that the run on is gone!

[KimMG]

There are two types of run-on. One is where the motor won't shut off. It is caused by vacuum leaks to the anti-runon valve. Moving the white/brown wire from terminal no. five to the white wire terminal will partially solve the problem and allow the motor to turn off when the ignition switch is turned to the off position.
The second cause is when the motor is actually dieseling. It is caused by vacuum leaks to the anti-runon valve.
Paul Hunt has covered this many times. I copied part of one of his threads.
http://www.britishcarforum.com/bcfor...off#Post441874