7 replies to this topic

[james.c94]

My mini keeps blowing the top fuse on the fusebox and I can't work out why. The only wire is a green wire, which I'm guessing is for my rear brake lights and indicators as they've stopped working. Anyone know what might be causing this, can't see anything obvious when I look at the back of the lights.
Cheers
James

[Doz1971]

Hi James. How old is your car and which model?

[minidaves]

if its the indicator and brake light switch, if you have a stage 1 kit check the reversing light swtch wiring. comman problem is for this to short out againest the exhaust

[jimnali]

The top fuse normally supplies the brake lights, reversing lights, indicators and heated rear window. Somewhere you have a damaged or trapped wire which is causing a short to earth. You can narrow it down by replacing the fuse and trying each circuit in turn until you find which one causes the fuse to blow.

A common cause of problems is tghe reversing light switch in the base of the gear lever - the wires melt against the exhaust and cause a short. I would guess that depending upon which wire is effected this may cause a permanent short or only when reverse is engaged. A temporary fix for this is to lift the front carpet and disconnect the bullet connectors leading to the gear lever (don't forget to protect the bare connectors.

[james.c94]

It's a 90' Mayfair mate

[tiger99]

The green circuit also feeds the anti run-on solenoid (if fitted) and the dim-dip unit. You can usefully get rid of the DDU by joining the blue/brown and blue/red wires amd insulating all the others. It never became a legal requirement, and it is far safer to get rid of it, as you remove one of the two major sources of sudden headlight failure.

As jimnali says, try operating one circuit at a time, to see when it blows. And, inspect all plain green (not light green) wires where they can be seen.

[bmcecosse]

Does it blow instantly when you switch on the Ign ? Otherwise -test out each circuit one by one to determine which is the problem. Are you fitting 35 amp fuses each time??

[james.c94]

Cheers for the help guys, the gear selector had worn through the reverse light wire causing it to short, problem sorted