Installing delay wipers on a 77 truck??

[Honky Lips]

I have searched all the google threads, and between all the guessing and obvious wrong info I am not 100% sure on what needs done. I have come to the conclusion that i need an early 80's wiper motor for this to work. so i picked up a motor for an 82 k1500 with delay. and went to the junkyard and got the correct wiper motor plugs.

Alright, I have 5 77-85 chevys. Im currently converting the older ones to intermittent wipers. Went to the junkyard and pulled 4 switches and modules. in my 80, swapped it in and it works great (as great as 80s intermittent wipers will work anyways).

now, in the 77, i tried all 4 setups and nothing works. just high speed and off.

I searched all the google threads, and between all the guessing and obvious wrong info I am not 100% sure on what needs done. I have come to the conclusion that i need an early 80's wiper motor for this to work?

the intermittent switch plugged right in. but the intermittent function does not work.. i have 4 switches/modules to try. brand new motor.

i need the wiring diagram for this setup with wire colors. the chiltons/haynes books only show 5 wires when there are six. im about to give up. anyone with good knowledge seems to not be around anymore or they didnt post up any info, just that they figured it out.

I got a wiper motor diagram from mitchel1 for an 83. but no wire colors and very minimal info to the switch.


SO, ANY OF YOU GUYS THAT CAN HELP ME OUT? FIND GOOD WIRE SCHEMATICS, DONE THE SWAP BEFORE? ANYTHING?

[hatzie]

77 had a rare orphan, one year only, delay wiper setup. RPO CD4. I believe 77 used the 73-76 wiper motor. There's an oddity in how the motor is grounded in the earlier units that makes it incompatible with the 78 and later delay module.

The common modules start in 1978 and changed when the dash switch was relocated to the column.

You'll probably need a 1978-80 wiper motor and 1978-80 wiper harness from the dash thru the bulkhead plug and on to the wiper motor.

Schematics are in my signature.

[1774btcrew]

I was fortunate enough to come up with 2 of the 77 only factory wiper delay set ups. They seem to be really hard to come by. I would have went with the 78 and newer but wiring is just one thing that I am not good at! The newer stuff sure is a lot easier to come by!

[Honky Lips]

well. im at a loss.

put an 82 wiper motor in, wired up the plugs to the 77 harness.

hi/low wiring was right white/black at motor to purple at the switch for high speed

blue/blk to gray at the switch for low speed.
tied the park switch gray wire in with the low speed wiring.

the blue/black park wire goes direct to the switch, so i ran a wire for it.

used the 77 harness for the power wire. 77 yellow/black to 82 white wire

grounded the switch ground wire in the cab.

and still no intermittent wipers. im baffled. i didnt hook up the squirters, but everything else was hooked up properly. and nothing.

im baffled. 6 wires. 2 days of messing around and i cannot get things to jive. tried wiring switch direct to motor in the engine bay and that didnt work either.

[1774btcrew]

You must have a lot of patience with wiring! The factory set ups I have for the 77s are stand alone parts and don't require any cutting or splicing into the existing harnesses.

[Honky Lips]

I Ordered an aftermarket potentiometer switch. going to eliminate all factory wiring and run new. im over it.