Chevrolet Repair: 1990 700R4 Square Plug Wiring, 700r4 transmission, salvage yard

Question
I have a 1990 Chevrolet half ton two wheel drive truck with a 5.7L motor and a 700R4 transmission. I was wondering what color of wire done what on the square plug that plugs into the transmission case. It has three colored wires and I wanted to know what color of wire came from where and what it controlled because my plug got pulled off and I need to wire on a new one.

Answer
Hi Mike,
Quite a lot of the chasis wiring is covered by the diagrams at Autozone.com...http://www.autozone.com/az/cds/en_us/0900823d/80/11/56/bb/0900823d801156bb/repairInfoPages.htm

but I don't think it will show you that.
What will really help is a book that GM had printed, separate from the shop manual, called wiring diagrams.
You can find one, and copy the pages you need, at the public library, in the refference section. Look for wiring diagrams for that year.
The shop/service manual may show it, but it is often harder to read.

A salvage yard might let you look at a connector. Or just buy the connector from them, and they will probably cut off plenty of wire with it, and you can just butt splice the wires.

Van