Wiring Harness Problems

[ThePenton]

Greetings all. I am trying to finish swapping engines from a 90 into a 93. Both are k1500's, but the wiring harness is pretty different. Biggest difference is in the cab. All the plugs match (using the 90 ecm) except one. Off the 90 it is just one red wire. In the cab of the 93 there is a plug with 4 wires, the big red one and a purple, yellow and green.
By the way, the harness off the 90 and the ecm are fine. The one off the 93 was burnt. Suggestions?

 

[DRAGGIN95]

Well just off the top of my head to start with, if both truck's are automatic then the 93 should have an electronic 4l60e and the 90 should have a 700r4, so the wiring and ecm are a lot different. I am not trying to be an ass, I am just trying to figure out exactly what you are doing.

 

[ChrisAU]

I thought 94's were the first year of the 4L60's?

 

[DRAGGIN95]

Every 93 I have ever seen has a 4l60e, now that's not to say that some didn't still have a 700r4 though.

 

[ThePenton]

Correct, very different

But yet similar. Spot on on the transmission, the 90 to 92 had the 700r. 93 & 94 have 4l60e and TBI and thus are the only two year models with that particular ECM and Wiring Harness.
I bought a 90 with a bunch of rust but a strong drive train and a 93 ext. cab with a bad engine - it caught fire right on top, just enough to melt all the wires. I thought it would be simple to pull the engine out of the 90 and drop it in the 93. Then I learned about the differences in the wiring harnesses. So, I have the 93 all put together, but no 93 harness. I was trying to use the 90 harness and ecm to at least make it drivable while I find the 93 harness and the different plug ins on the engine.

The wiring harness off the 90 looks very different, but most of the plugs are the same except the ecm -red and blue and more rectangular on the 93 and the plug with 4 wires, the big red one and a purple, yellow and green. I am sure using the ecm and wiring harness off the 90 will cause me problems with the electronic overdrive -4l60E-, but I thought I could it least fire it up to check everything out with 90 ECM and wiring harness until I can find a 93 harness -remember the 93 had an engine fire and the wires all melted.

So, what is the least expensive and fastest way to get this truck on the road?

Thanks,

Ted

 

[DRAGGIN95]

I would hit the salvage yard's and find a 93 or 94 harness and matching ecm, around those older dash truck's harness's don't go for much at all.

 

[Joesgarage]

I thought 94's were the first year of the 4L60's?

Late 93 had 4L60E's

Wasn't 94 the first year for the PWM tranny? and it had the better PCM