Thread: S10 Swap how to
View Single Post
Old 08-17-2014, 11:19 PM   #98
Registered User
skymangs's Avatar
Join Date: Apr 2010
Location: Algona, IA
Posts: 1,703
Re: S10 Swap how to

I almost forgot. Somewhere near the beginning of this thread, I was asked to discuss wiring harness options. Basically there are 3 in my book.

1. If you are retaining the S10 4.3L with TBI, I use the stock S10 harness and ECM. Be sure you label everything before you unplug it if you aren't familiar enough with the harness to recognize the connectors.

IMPORTANT! BE SURE YOU ARE USING A KNOWN SYSTEM! In other words, before you dis-mantle the S10, be sure to drive it and identify, diagnose, and repair any electrical issues prior to the swap. Diagnosing electrical gremlins on a harness after it's been apart and flexed, and moved around and re-connected is NO FUN!

Using the S10 harness is pretty straight forward. I mount the ECM behind the glove box (above the stock heater box). I run the ECM harness though the firewall on the right side of the engine. All the engine connectors will be re-used. The wiper plug can be removed, delete all the wires but the switched power, then lengthen it to run it into the cab. I've built 4.3L trucks that still have the factory ABS and cruise control even (note: to have the cruise control function, you need the S10 brake light switch).

I also delete the courtesy lights (under dash) and remove the stupid key in/lights on buzzer. The dash cluster plug is a pain, but pin-outs are available on the internet. See attached Pin-out for 83-93 S10's. Obviously the oil, temp, and voltmeter wires are the sending unit wires for aftermarket gauges, the left/right turn, bright ind. and SES wires must be hooked to individual lamps, etc. If you do not have basic wiring proficiency, do not attempt this! get professional help.
Attached Images
File Type: pdf S10 dash pinout.pdf (98.3 KB, 845 views)

Last edited by skymangs; 08-17-2014 at 11:35 PM.
skymangs is offline   Reply With Quote