NytWolf

I got pretty much everything on my 3.4 swap running correctly ...

That is, until I switch it to 4WD, then the engine stalls. The EFI fuse in the engine bay fusebox blows as soon as I switch it to 4WD. Consequently, the "4WD" dash light stays on even after switching it back to 2WD.

If I disconnect the 4WD sensor harness at the t-case end, it doesn't blow the fuse, but obviously the "4WD" light does not come on. This is with the A/C harness still connected.

Now what I've found is, if I disconnect the harness to the A/C blower/amplifier unit, then everything works fine. I can switch it to 4WD and have no problems. This is with the 4WD sensor connected.

Did I miss something with the A/C circuitry? I haven't done anything to the A/C circuit, and I have the 3.0 amp, 3.0 blower, 3.0 condenser, etc, with a 3.4 compressor. I have the 3.0 fusebox, 3.0 4WD sensor, 3.0 5-speed transmission and t-case.

I have traced the wiring and the short seems to be on the A/C circuitry area somewhere. There is no short on the end that goes to the 4WD sensor.

hamish_18

what wire did you hook up from the ac stuff to your ecu. What year vehicle, and what year motor?

NytWolf

I haven't modified anything from the AC stuff to the ECU. Everything is still stock.

My truck is a 92 extracab and the 3.4 is from a 2001 Taco.

hamish_18

That doesn't make sense. unless you swapped all electronics, and ac lines and evap box over to your 92. If not you had splice a wire from the c1 or c2 plugs to one of your ecu plugs. Read the a/c wiring thread that ukrunner and I discussed this all in. If you haven't done this then the two systems are still separate, and the issue was there prior to your swap. unless you de-pinned your c1 and c2 plugs completely for some reason....

NytWolf

I had read the thread with you and ukrunner discussing this, but I haven't done anything to my AC circuitry. I have depinned some of the C1 and C2 plugs to make things work, but as far as I can tell, everything seems to be correct. The only thing I can think of is, the fused +12V coming into the harnesses may be wrong somewhere. That is, I may have spliced a wire incorrectly on the 4WD sensor circuitry on the C1 or C2 plugs.

So just to get this correct, if I am using all 3.0 A/C components, I should not have to change any of the wiring from the A/C condenser, A/C amp, and blower unit. Is this correct? If this is correct, then I have to retrace my C1 and C2 plugs.

hamish_18

that is correct. It's a separate system. and you need to just connect the I think b-w? or b-r wire that is going to the mag. clutch and amp, to the ecu. but it's just one wire. Everything should work then. I would double-check the rest of your wiring..

NytWolf

Yep. Will do then. It won't be for a while though. All booked up until middle of August.