MGB GT - won't switch off !!

[1966marden]

I have a 1978 MGBGT that has just decided it wont turn off! I can even remove the ignition key, plus disconnect the multi-plug under the dash to the ignition switch... it just keeps running. I have to stop it by disconnecting a live feed wire at the fuse box! A little unusual even for a classic. I have replaced both the starter solenoid and ignition switch relays, by the fusebox in the engine compartment, but this has not solved it. I have double checked all wires go to the corect terminals on these relays. The ignition key has always been very hard to remove from the lock by the steering column - is this a clue? Any helpful ideas welcomed !!

[Uhura_Fighter]

Ignition key is hard to remove as they just were not built that well (I have a 79 bgt) you could just slip it into fourth and stall it till you fix it.

See here


It is something I have heard of before so you could try a few mgb specific sites


Good luck

[Mucus]

Had the same problem many years ago. Turned out to be a knackered relay near to the fusebox. Easy fix!

[mulsanne]

I remember having a problem like this in my '78 B GT. As a rookie owner back in 1982(!!!!), I remember stumbling upon the three in-line fuses by the main fuse box on the offside wall of the engine bay.

I remember being surprized that two of the in-line fues seemed to have been connected wrongly, ie a green connected to a white/brown and vice-versa.

Completely ignoring the fact that the car had operated perfectly ok like this, I changed the connections so the greens were together and so were the white/browns.

The result was the car engine would not switch off on the key, like you describe on yours. Putting them back to the "wrong" colour connections sorted it.

I have just been out to the garage and checked (yes, I still have the car after 27 years!) and it's still connected with "wrong" colours but works!

Might be worth checking yours.

Hope this helps,

Ps, I now also run a TVR cerbera so I am used to bonkers wiring!