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MG MGB Technical - OD wiring connection

I'm in the process of swapping an O/D tranny and was just curious where the Over Drive column switch plugs into O/D harness. Is it in the engine bay? I don't have a good manual on hand and figured the bbs could give me a quick answer. Just feeling a bit lazy and cramped for time, otherwise I would put some hours in on google.

cheers,

-Bill
Bill Mertz

Bill,

Mine isn't a factory installation, but for what it's worth, the wiring from the transmission roughly follows the path of the fuel line and clutch hydraulic line to the engine bay.

If you do it like that, then I guess you'll have to decide if you want to run from the column to the engine bay, or from the engine bay to the column. Don't waste too much time on that decision.

So, there's a lazy answer. A book may not show it anyway.

Charley
C R Huff

In the engine bay - find the thick wire loom
that comes up from underneath the car - along
the passenger side (starboard) inner wing.

At the top of that wire loom, or, just below the
starter relay that is adjacent to the fuse box
- you will find a fistful of bullet connectors.

Look for an unused bullet connector (white wire)
hiding somewhere in that loom.

That's where the OD connection is made.

It'd be a good idea to install an inline fuse
along the OD circuit as it is unprotected.
Daniel Wong

It's in the location Daniel said. The wire coming from the column switch should be yellow. Hooking it to a white wire will bypass the column switch, the overdrive would be one anytime the ignition switch is on.

Clifton
Clifton Gordon

There are three harnesses joining together near the fusebox in the mass of connectors. The biggest is the main harness, the next biggest is the rear harness going down and to the back of the car, and the smallest is the gearbox harness going down under the tunnel closer to the middle of the car. This contains the reversing light wires as well as the OD wire.

All cars with the column wiper switch had the OD manual switch and yellow wire, regardless of whether they had OD or not. It is quite common for owners to use that yellow wire for the fuel pump instead of the white and so use the manual switch as an immobiliser.

The wire from the main harness was yellow while the OD manual switch was on the dash and column, white when it moved to the gear lever in late 77.
Paul Hunt

Thanks for all the replies, Looked in the engine bay and found it right away.

-Bill
Bill Mertz

This thread was discussed between 15/08/2008 and 24/08/2008

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