MonteHall

Update:
Got the car running, the overdrive now works. I wired from the pressure switch, to a spst switch, to the battery. I just have to make damn sure that the od stays off until I'm in a high gear.
With that in mind, can I just run my switch from the first gear switch to +12v? Then I would be able to use it and not have the oppurtunity to leave it on in first...

scorp508

I don't know about 84, but in later years the ECU knew when the car was in 1st gear and combining that with other conditions like MPH, TPS, and RPM it would or would not let the OD engage.

The OD could stay on in 1st if you were downshifting from 2nd+OD to 1st. It would leave the OD enabled so there wouldn't be a big 2 shift change in RPM and would leave OD on until the TPS changed in a positive direction.

It looks like you have them, but if you need the wiring diagrams I have them for 87. I also have the whole 4+3 troubleshooting manual somewhere around here.

MonteHall

It's been carb converted, so the ecm is out of the picture.

Here is the wiring I'm looking at

ProjectC4

Yes, I have an '84 too and that's the way to do it, in series with the first gear switch - I have seen posts on here from people who did.

I did not know that the later models held it in high for first gear on deceleration.

MonteHall

Done... Have to see if it works out tomorrow