Manual swap M46 wiring harness into 91 240

[dandeluca]

I am nearing the the end of my manual swap. I have purchased the upper and lower harness for a m46 from Dave Barton’s site. I also have an overdrive relay. My question is how to use the relay.

There are some plugs on the harness that are meant to be connected under the dash.

Would I be right to assume that these plugs won’t exist on my car?

I can follow the wording diagram and hook up power, ground and an overdrive light. I am just not sure what exist on my car.

[dl242gt]

You are probably going to have to run the power wire from the fuse box to the relay. For the overdrive light in the cluster you can use the up arrow light from the automatic overdrive. I can't recall any plugs under the dash you'll need or may be existing. The overdrive up arrow would have a wire running to the old automatic relay so you can splice into that easily. Just be careful to insulate the wiring where it goes through the shifter hole.

[AnthonyHardy2]

If your car originally had an automatic with overdrive (AW7X) and you have the push button shifter and relay for the M46 I think you can just replace the automatic relay with the manual one and connect your old overdrive button wires to the ones in the manual shifter. IIRC the only difference between the manual and automatic overdrive relays is the automatic relay is on by default and the manual one is off by default.

[dandeluca]

Originally Posted by AnthonyHardy2

If your car originally had an automatic with overdrive (AW7X) and you have the push button shifter and relay for the M46 I think you can just replace the automatic relay with the manual one and connect your old overdrive button wires to the ones in the manual shifter. IIRC the only difference between the manual and automatic overdrive relays is the automatic relay is on by default and the manual one is off by default.

Yes I have been looking over the wiring diagrams (and actual wires) the last few days. Basically I should put the new m46 relay where the old AW70 relay was. I can use the 12v+ wire from the Aw70 relay to power the new relay. I can also tap into the wire that ran to the overdrive warning light from here and use that as a "overdrive on" light. I can just crimp on some new female bullet style connectors to connect into the new wiring harness that I bought from Dave Barton.

Other wiring includes jumping the neutral safety switch and hooking up reverse lights. These are fairly simple you just have to find the wiring jacks that hooked up to the switch that was in the auto shifter. (They are on the drivers side down at the bottom of the center stack.

The wiring harness I bought has all the wires and connectors that go to the actual M46 and a socket for the relay. Those include overdrive solenoid, 4th gear lockout switch and the momentary overdrive switch at the top of the shifter.

[hiperfauto]

Originally Posted by AnthonyHardy2

If your car originally had an automatic with overdrive (AW7X) and you have the push button shifter and relay for the M46 I think you can just replace the automatic relay with the manual one and connect your old overdrive button wires to the ones in the manual shifter. IIRC the only difference between the manual and automatic overdrive relays is the automatic relay is on by default and the manual one is off by default.

Just swapping the relays won't work. The AW7x relay toggles power between the dash light and the OD solenoid. The M46 relay powers the dash light and the solenoid from the same terminal.