Ok, so I`ve got a 96 Jimmy, 4x4 with a 4l60E. Auto.

I`ll start from the beginning. Bit of a story.

Started the truck this AM, once started, smoke started billowing out of the engine compartment. Smelled electrical. Shut the truck off, grabbed some tools and in a panic, took the negative off the battery. Upon inspection, a wire going to a 4 bolt junction on the drivers side firewall had come out of it`s casing, and was shorting out, melting and starting on fire. I repaired and recrimped the wire, and tried to start the truck with it DISCONNECTED. No power at all at ignition. (Interior lights working though.) Seems like an ignition wire.

Once fixed, out of the driveway, the truck was sluuuuugggish. Felt like I was trying to start off in 3rd or something. Was able to manually shift from 1st to 2nd, but starting in 3rd, barely any power. Brought it back home, hooked up the ol`scanner, and got these codes:

753, 758, 1860, 1864, 1886.

Everywhere I have read, leads me to believe that the tranny is in what they call `limp in mode`. The speedo, tach, and odometer all WORK. The PRND321 light on the instrument cluster however, does NOT work.

I pulled out the meters, and proceeded to start checking.

Pulled out the TRANS 10A fuse in the fuse panel, checked for continutiy, and the fuse was NOT Blown. Swapped the fuse with the CTSY fuse, just as a double check, and the fuse was working fine. I then found a good ground, and checked the actual TRANS fuse slot, in OFF, ACC, START, AND with the truck running. (I should add the battery is at a healthy 14v whilst running.) And.......... No voltage whatsoever. Penetrated the wires behind the fuse panel, checked both the hot and neutral coming off the back of the fuse panel, and still.. nothing.

I then proceeded to rip the interior apart. Got to the ignition switch.

With the keys in and to START, all wires coming off the bottom of the ignition switch had power. EXCEPT the yellow. Tried to follow the wires back, but no dice. way too tight. I`m stumped. Next I will be checking the plug off the tranny.

That being said, If i`m getting 0 volts off the fuse panel, obviously the tranny will not be getting power. Could I in theory jump a hot lead onto the hot going to the TRANS fuse slot... or would I be causing myself issues.

What am I missingÉÉÉÉÉÉ

Thanks in advance!

 

The white wire at the ignition switch runs to the trans fuse through two connectors, C206 is the connector between the ignition switch and the harness and then C200 is the front harness connector. The harness should then lead into the fuse panel.

You could try running a fused jumper from a switched ignition source into the fuse out to the transmission if you cannot find the break in the circuit between C206 and the fuse box.

 

Awesome. That's pretty much what I was looking for. I'm going to try this tonight, hopefully, it'll solve the problem.

Thanks for your help man.

 

And on another note, would this indicate the ignition switch has blown?

I still get 12 volts to all wirs on the switch. Even took it off and cleaned it.

I'm going to take a picture of the "junction" on the drivers side firewall and hopefully someone can identify it. This is where the short happened.

 

If you have +12V on the white wire out of the ignition switch as indicated on the wiring schematic I posted, then the ignition switch is working properly.

 

So it turned out that I had a wrecking yard special ignotion switch, and the wire colors were all different from the diagram.

So I threw in an inline fuse, and jumped off a switched 12v source off the ignition, tapped into the power wire going into the TRANS fuse, and low and behold.... IT WORKED. Tranny is back to normal, ALL codes erased, and truck is driving normally. Even fixed some loose wiring with my stereo while I was at it, and fixed a speaker that wasn't working. The clown who owned the truck before me had taped wires together off the steering column and they were coming apart, so I had to crimp those all down too.

Anyways, thanks for the help, and hopefully this helps anyone who ever has the same problem.

 

The 95-97 trucks are different from the 98 trucks that are covered in the article I wrote, but the schematic I attached above is applicable to your truck. Glad you got it figured out though!