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MG Car Repair/mgb wiring to transmission


I am trying to restore an 80 mgb roadster I was fortunate (?) enough to find in decent shape.  It's been sitting for over 10 years and someone before me started to take it apart but never marked anything.  I'm wading thorough a lot of issues but right now am stuck on the wiring loom running to the gearbox.  It was all disconnected and some wires are cut.  Here are my main issues:
Reverse switch (left side of the gearbox) - is it polarized?  How do I know which lug which wire (green and green and purple)gets connected to?
TCSA/O/D switch (right side of the gearbox)- again, is it polarized?  How do I know which lead (yellow and yellow and purple) goes on which lug?
O/D solenoid - this part of the wiring loom is cut.  There is a yellow lead which runs back up to the TCSA/O/D switch and a yellow and purple lead which is also cut an the end near the O/D solenoid wire and further up in the loom near the TCSA/O/D switch.
O/D manual switch in the shifter knob - this has a red and a green lead but both have been cut and I can't find anything they are to be reconnected to or plugged into.
I've tried following the diagrams in Bentley's and the ones on line from Hanes but must admit I'm stumped.
Thanks for the help!

Probably not going to be much help however, you have already done the right thing by getting a wiring diagram and (trying) to follow it. One of the best things you can do.
Regarding the reverse switch- shouldn't matter which way it's hooked up unless the terminals are different sizes just fit the wires where they fit. Same for the O/D switch. Same for the O/D solenoid. Try to find the end of the harness where they were cut-then match up the colors. I'm sure you realize that. Other than that, I really don't have anything else I can suggest. Trial and error and follow the diagram with the wire color guide codes, like B, R, P, N, etc. for the colors and tracer colors on the wires. The other cut ends of the wires must be there somewhere!

Good luck!

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Brian Warmuth


General questions regarding most MG autos from 1950 through 1980 - primary are the TD, MGB, Midget and MGA.


Over 30 years of working on and restoration of MGs

Ohio Chapter New England MGT Register, AACA

BA, and MS, from WVU

Awards and Honors
several local regional awards for restorations

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