4 plus 3
Thread Starter
Intermediate
Joined: Jul 2016
Posts: 28
Likes: 0
4 plus 3
Hello all. me again. My engine wiring harness is all hacked up. I bought a used one from an 85 in good condition but that car had an automatic trans. mine is manual 4 plus 3. My harness has 7 wires going to the manual trans. The one i bought from a automatic only has 5 wires. I have heard lots of negative things about the overdrive so my question is 1 what do those connectors do? 2 Should i get the right harness and hook it all up? Maybe the overdrive works without the connectors? Any help will be greatly appreciated. Thanks
Le Mans Master
Joined: Sep 2013
Posts: 6,192
Likes: 750
From: near the thumb in the mitten
You really need the correct harness. If you have 85 and 86 FSM electrical diagrams and a lot of time you maybe able to rewire 85 harness to be the same as the 86 you need. You will need to verify every wire is in the correct position and going to the correct component. Both at engine and dash.
Last edited by Kevova; Sep 8, 2016 at 08:57 PM.
Melting Slicks
Joined: Jan 2014
Posts: 2,192
Likes: 381
From: Lunenburg MA
The rear most connector on the trans (not including the speed sensor) controls the OD. It's a single spade in white plastic. If you apply +12 to this it will engage OD as long as the car is moving and the OD works. You could put a switch somewhere until you get around to doing it right. Best to only use it in 4th gear at 50+ MPH and always use a fuse at the power source. 10A would be plenty.
Thread Starter
Intermediate
Joined: Jul 2016
Posts: 28
Likes: 0
4 plus 3
The rear most connector on the trans (not including the speed sensor) controls the OD. It's a single spade in white plastic. If you apply +12 to this it will engage OD as long as the car is moving and the OD works. You could put a switch somewhere until you get around to doing it right. Best to only use it in 4th gear at 50+ MPH and always use a fuse at the power source. 10A would be plenty.
Thread Starter
Intermediate
Joined: Jul 2016
Posts: 28
Likes: 0
wiring harness
You really need the correct harness. If you have 85 and 86 FSM electrical diagrams and a lot of time you maybe able to rewire 85 harness to be the same as the 86 you need. You will need to verify every wire is in the correct position and going to the correct component. Both at engine and dash.
