This is odd. The washer pump motor itself works when I jump it to the battery. That is, when one wire is hot, and the other ground. But, the power wires that go to the washer pump motor are BOTH 12 V positive, and the wires don't look tampered with. What am I missing? I would think there ought to be one hot and one ground.

There is also another pigtail in the same bundle as the washer pump, with a different sized plug. Anyone know where this is supposed to go?

Under the driver seat is an electronic box of some kind. Is this stock? If not, probably POs amplifier or alarm equip.

Next to the hood release lever, just above the left front speaker is another metal box. It has an insignia on it that looks like the Mitsubishi symbol. Is this stock, or another of POs modifications?

 

Power goes to the motor, then grounds through the switch, the wiring diagram doesn't show a relay or anything else in the circuit. Either the switch is bad or the wires are shorted/broken somewhere, find the connector for the switch and hook up a meter to the black and yellow wires and see if the switch works. If it does then I'd just run new wires from the switch to the motor, and check the ground wire.

 

That's for the sub-zero assist bottle pump. Squirted antifreeze into the carb. Most cars don't have one fitted.

Not sure about that one - - my 80 doesn't have anything under the seat but carpet (and mummified crumbs sometimes)

That's your ECU. 'brain box.'

Not sure on the answer for the washer; Are you saying that, with the pump disconnected, both wires are showing +12v referenced to ground?

 

I have the subzero pump. I'll check to see if the pigtail isn't hooked up.

Yes, when the washer switch is activated, it sends 12+ thru each wire. An easy fix would be cut one wire and ground the other washer motor contact. It worked if I jumper wired it that way. The box unjder driver's seat uses DIN connectors, I'll have to really get a close up on it with a flashlight.

 

The Blue/yellow wire goes to the switch. It should be grounded when the switch is activated and open when the switch is at rest. The Blue/black wire should have 12v anytime the car is on.

Silver box under dash may be the cpu for the wipers. The wires going into the cpu are blue with different stripes. The Blue/yellow wire from the cpu connects to the Blue/yellow wire going to the washer motor and switch. Does it work if you unplug the cpu?

Stock audio amplifier under seat. There may be another under the driver's side storage bin along with the cruise control module.

 

Great info guys, thanks. Makes sense about the two metal units being factory, the install is too clean to be the PO's.