81 cj7 wiper motor issues

[mnoldfart]

I Bought an '81 CJ7 and the guy said it had a brand new wiper motor and it was installed but he hadn't had a chance to hook it up yet. I plugged it in to the back of the switch and found a disconnected red wire with a white trace and hooked it up for power and didn't get anything. I figured a new motor, so it must be a bad switch so I bought a new switch. It's a 3 wire motor. I plugged it in, plugged the red in and got nothing again. I found a wiring diagram on-line which showed what color wires go to what posts on the back of the switch and everything looked good. No luck. I yanked the motor and went to the front of the jeep. Opened the hood and ran a wire to the battery and the motor worked. Now thinking the red wire with the white trace was bad I ran a new red from the battery with an in-line fuse and hooked it up and got nothing.
I know the motor works. The switch is new so it should work. What am I missing? the old switch thrown in the trash a while back so it's long gone.
I would like to have my wipers working for those rainy days and snowy days coming up.

 

[Lumpy Grits]

WELCOME
Did you have the ign. switch 'ON' when you test'd it?
Also-Look for a bad ground issue-
LG

 

[oldjeeplady]

Welcome from WI!

I had a similiar problem on our 79 CJ7 . It came with a 4 wire motor, but it was not installed and not the original. The biggest problem I had was using wire colors to decide the connections. Here's how I solved the problems:

Yes, having a schematic is great, but just connecting wires based on color didn't work. So I made a bench test setup with a fused hot jumper, another jumper for the ground, a 12 volt battery on the bench and figured out which wires controlled what. For this test I connected the negative battery terminal to the motor case for the return current (ground if you will). So I identified which wires caused the motor to run in low and high speeds.

Then I removed the switch from the dash and tested it with an ohm meter to figure out which connections were connected in each switch position. Next I put the switch in my bench test set up and connected the wires based on what I had learned and not wire color. I was able to get the motor to run in both speeds and even park correctly on the bench (after I took the motor apart and cleaned the finger contacts that are part of the park circuit). Our CJ7 does not have a washer motor, so there was one connection I did not use on the switch.

I discovered not all wiper motors had the same wire colors even if they a for the same CJ. So make the connections based on function and not wire color. When I installed the motor in the CJ, I ran an additional wire from the motor case to a ground instead of just depending on the steel windshield frame and hinge bolts for a ground connection. This may be the only problem you have.

Like LG said, once installed you will need the key in the run position. I was able to get the wiper motor to run in both speeds and park correctly when I first installed it. Only a few weeks later the motor didn't park correctly, but the wiper motor still works in both speeds. So we just play with the switch until the wipers are where we want them. Our windshield washer is me with a hand held spray bottle filled with washer fluid.

Hope this helps and good luck!

 

[HackFabrication]

Welcome!

I discovered not all wiper motors had the same wire colors even if they a for the same CJ. So make the connections based on function and not wire color.

^^^This. Aftermarket motors are notorious for not working correctly with the factory CJ wiring. I bought a 4 wire that acted similar to yours. Take the time and figure out what does what, and then hook it up accordingly.

Or search for a good used genuine factory motor, which should work without all the drama.