Attempted a crew cab build for the last few weeks. Got drivetrain switched over, & even started. Used engine & wiring harness from the '89 donor, into an '84 W350 srw. Had it started last week, but no gauges or dash lights, signals, or tail lights. Does anyone have a schematic they could pass on to help. I imagine I have a ground issue, among other things, but without some map it looks like spaghetti to me. Thanks in advance!

 

did you swap the inside wiring also ? everything from Donor will swap right over makes it alot easier .Also there are a few ground wires under dash that have to be hooked up to make thing's work right. send me a PM with your e mail address theses truck's are really easy to do .

 

We did use the interior harness as well, however it was pretty well dismembered after the previous owner. It's likely in the process of cleaning up & deciphering what was what, that we mislabeled or just lost connections...The truck still starts & runs though!

 

There's a 91.5 wiring diagram in the sticky. I successfully used it on my truck. Made things a lot easier. Good luck

 

You need an FSM=Factory Service Manual
Very,very handy, even for a wiring idiot like myself. Has many other uses also.