My Haynes manual wiring diagram might as well have been written for a motorbike for all the good it is :rant:

Manual shows washers controlled off the back of the wiper motor assy,
this site http://iotech.no/corvette/index.htm Shows a control box?? in the jack compartment (and there are 2 control boxes in there)

The washers haven't worked since I have had the car. I have taken the plug off of the washer pump, and with a meter between either of the 2 connections and ground, I am getting 12V. It makes no difference when I operate the switch.
Can someone point me in the right direction before I go mad?
Thanks in advance.

 

On the windshield washer motor the 18 AWG white wire is circuit 93A.
On the windshield washer motor the 18 AWG pink wire is circuit 94A.

Circuit 93 (white) is the windshield motor feed.
Circuit 94 (pink) is windshield washer switch to the washer.

Both 93A and 94A circuits run to the firewall block that connects the engine compartment wire harness to Instrument Panel and Dash.

Wires 93B (white) and 94B (pink) run from the windshield wiper motor to the firewall block. 93A and 93B share the same terminal slot. 94A and 94B share the same terminal slot.

Under the dash, circuit 94 (A&B) connect to circuit 994 an 18AWG pink/black wire. Circuit 994 runs to the controller assembly for the intermittent wipers, where in-turn, it runs circuit 94 (pink wire) to the washer/wiper switch.

Under the dash circuit 93 continues as a white 18AWG wire that runs to the controller assembly for the intermittent wipers.

The GM shop manual for the 1980 has circuit operation descriptions in the electrical section that should help with troubleshooting. The NCRS publishes good wiring diagrams, as does Lectric Limited.

When the ignition switch is in the "Accessory" or "Run" position power is available to the wiper/washer controller assembly.

When the wash switch is momentarily closed, the washer pump motor is grounded, and current flows through the controller assembly to operate the washer.

The washer can be operated with the wiper switch in any position. If the wiper switch is OFF, the controller assembly turns on power to the wiper motor for 3-5 sweeps then turns power OFF.

 

Do you have those circuit diagrams? Could you email them?
Wires to washer pump are black & red (pink?) I think I'm going to have to improvise regarding the colour scheme of the wires, But knowing what the circuit looks like is half the battle.

You say ground is applied to washer pump via switch and control box. Why am I getting 12 V on both wires to the pump?
Thanks

Just had a look at the Norwegien site. Is that the diagram you are quoting?


[Modified by Col-UK, 11:14 PM 2/9/2004]

 

Reference material is the NCRS wiring diagrams, and the GM Corvette Shop Manual for 1980.

I have new wiring harnesses on my 1980. (Lectric Limited) The new harness is IDENTICAL to the old harness in terms of wire color, wire guage, and connectors. The wires to the washer pump are pink and white.

Sounds like someone has spliced into some wires (red and black). I have no way to email you the wiring diagram, and I would suspect that a scan might not pickup the fine detail in any case. The diagrams are on several pages and a paper version is what you need. The 1980 GM Shop Manual will be the most help on electrical troubleshooting.

 

Thanks for advice. I will try and get shop manual.
I think you're right about wiring mods, it's not the only thing I've found!

 

Col-uk

I've just emailed you a circuit diagram of the system - I put it together myself when I was trying to fix mine.

The reason you get 12V at each side of the pump motor is that it takes its feed from the PERMANENT 12v supply for the wiper motor. So to make sure it doen't run all the time, they designed it to have 12v on both sides, ie no current will flow. Then, when you push the wash button, you ground one of those two pump wires VIA the controller. Then the motor runs. I guess putting the controller in the loop is their way of letting it know it's time to do the automatic 3-5 wipes when you push the wash button..

:cheers:

 

Email rec'd & printed off. This makes a lot more sense. I will look later tonight and see if I can get them working.

 

Hi Col,
I know exactly what you mean! Grab yourself the 1980 manual (got mine from Ecklers). It's expensive but worth every penny as it's turned all my other manuals into dust collectors! I think mine cost $70 but with the current exchange rate you could get a bargain :)
Good luck
Paul