auto to manual swap wiring 87 BII

[Elutheros]

I've spent hours trying to find a definitive answer on the forums, and finally found the answer through a link to another forum. I installed a FM146 in my BII after tossing the AL4d. Ihave not touched the under dash wiring, so the clutch interlock bypass is still in place. I left the AL4D wiring harness intact so far.
Here's what I have:

You must connect three wires together from the 5 pin plug: Pink, Red/Blue, and Red/White--this will make the ECU think the trans is in neutral/Park and allow it to start and run.
The small 2 pin plug is unused. I found by connecting the Black/White and Purple wires I can get the B/U lights on--but they just stay on no matter what the shifter position, so you must take the smaller of the two plugs which goes on the red connector on the trans and connect it to these two wires.

I also have the harness from the donor vehicle:

This red plug is for the reverse light plug--the smaller of the two above.

The plug in the photo below connects to the NSS--neutral sensing switch on the manual trans--essentially doing nothing since you are going to bypass it by connecting the wires on the 5 pin plug together.

Finally got it to work by connecting those 3 wires together---Pink, Red/Blue, and Red/White.

 

[Elutheros]

Okay, here's the answer to my question:

On the 5 pin auto trans connector, I connected the Pink, Red/Blue, and White/Black wires together. This enabled the start/run by making the ECU think the transmission is in neutral/Park.

(remember, this is a 1987 BII I'm working on--yours may have different colors)

The other two wires go to the reverse light switch. You can just cut a section off of the manual trans wiring harness and connect it to these two wires. If you have trouble identifying which wires go to what, turn on the ignition switch and check for 12 volts at one of the wires (black/white on the 87). The unused wire next to it is the other one used for the reverse lights--purple on the 87. Hope that helps.

 

[samx227]

Thanks for the link to this. I will give it a shot this week!

 

[SenorNoob]

Don't forget, if you bypass the neutral switch there and have the clutch switch still bypassed, the starter will move the truck when it's in gear..