MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGB Technical - Transmission Wiring

Removed the non overdrive transmission from my 80 LE to replace front seals and have a couple of wiring questions. The transmission was a terrible mess of oil and dirt so didn't closely look at the wiring color codes when disconneting the reverse lamp and transmission interlock. The connections on the switches don't have any unique markings (positive, negative, for example) so I'm unsure if there is any specific wire color to pole orientation. Each has 2 wires. Wiring diagrams seem to indicate the reverse lamp switch is not polarity specific. The transmission interlock switch is probably useless anyway. The car likely had the CEI distributor, but a PO changed it to a 25D. I sent the 25D off for rebuild and had pertronix installed. I'm assuming that so long as I don't switch the reverse pair for the trans interlock pair, it doesn't matter what color goes to what pole on each. Anyone know if that's a correct assumption?
Rick Penland

Neither switch is polarity sensitive, either wire can go on either terminal, as long as you keep the right two wires on each switch.

The reverse light switch is on the right side of the gearbox and has green and green/brown wires.

As you don't have overdrive the other switch will be for the 4th gear only Transmission Controlled Spark Advance solenoid in the vacuum supply to the distributor - if you still have it. The wires for that could be yellow and yellow/purple.
PaulH Solihull

Thanks, Paul. I'll hook them up and finish reinstalling the transmission.
Rick Penland

This thread was discussed on 16/02/2011

MG MGB Technical index

This thread is from the archive. The Live MG MGB Technical BBS is active now.