Hey, I just got my 86 4x and in 4low I went through a puddle, then my truck quit. I looked under and a mad clump of wires were wrapped around the driveshaft. After I sorted it out, I ended up with a plug with a pink/black and a solid black wire. the plug is attached to the fuel filter right on top. I figure this is important. I also had a plug dangling with two light blue leads coming from it. Can anybody tell me where these go? I got a neutral pressure switch open circuit code. thanks.

 

Wow! ****ty luck! With an 86 I can't help you too much, because my wire diagrams don't go back that far. However, I'm sure someone will chime in soon...

Where did the mass of wires come from? Was it wrapped in wire loom, tape, or anything??? It obviously wasn't secured in place!

Where do the "plugs" appear to go? The transmission? Fuel tank?
Are your O2 sensor wires secure and intact? Got a digital camera?

 

the pink/black and black one is in the frame rail pointing toward the rear, but the wires could really go anywhere from there. the one with two blue wires was too long to tell where the original location was. all the wires were wrapped in wire loom. the huge bunch of wires comes down from the firewall under the brake booster and goes straight down to the frame rail.
The O2 sensor is in the exhaust?

 

There is no plug on the fuel FILTER, but the fuel PUMP is probably on the DS frame rail and likely where some of the wires need to go.

I too can't help with the wire colors, but I'd suspect the Lt Blue wires attach to the transmission, if your only issue now is a neutral switch code.

 

These diagrams from TRS may helpDiagrams

 

I got it running again, the wires were pulled off the secondary fuel pump. It looks a lot like the fuel filter on my 94. I still don't know what the blue wires were for, but it runs fine. Thanks for the help.

 

You never fixed the NPS Open Circuit problem??? Maybe the blue wires went to that switch.

 

I haven't been able to figure out what the nps does. I haven't tried my code reader since i got the fuel pump going. What does it do?