cmarr6

My windshield wipers on my '85 run too slow. Even on high they run too slow to keep up with a steady rain. I have replaced the motor twice with JY motors. I thought maybe I just got another weak motor, but I wouldn't think all three were weak???? What could cause the wiper motor/motors to run slow?

TheTynosaur

Could be the wiper transmission. I don't know if jeeps call them that, but the part that connects the motor to the wipers themselves

XJwonders

U mean the linkage?

TheTynosaur

Yeah I don't know the name, I have slow wipers on my jetta, so I know that's what vw calls it, but no experience with such a thing on jeeps

cmarr6

Yea, Iv'e thought about the linkage. There are bushings on the linkage, aren't there? But if these go bad, they wouldn't bind making them run slow, or would they?

cruiser54

Is the ground to the wiper motor good?

cmarr6

How would I test it? The motor does work, so just assumed it wasn't the wiring. Could I just run a ground wire from the existing harness to a good ground somewhere in the area?

XJwonders

Never assume! Verify instead! Check the wire connection at the motor and wiggle it while it's running, see if it improves.

Check the ground, take it off and sandpaper it and put back on.

cmarr6

Okay, thanks, will try that this weekend. But, if that doesn't work, could I add another ground wire and ground it to a good ground just to make sure?

XJwonders

If u checked the ground by sand papering the metal the wire touch, why would u run another ground wire? It's already been improved by the sand papering.

cmarr6

Just want to ensure good ground. I know i've seen that advice dispensed on here before, to run additional grounds to ensure a good ground. Thought maybe it would be a good idea here too.

Pelican

Check voltage at the motor with a meter and let us know. While you are at it check voltage at the circuit breaker in the below dash fuse panel.

cruiser54

You can never have too much grounding.

Black wire at wiper motor is ground. It ends up grounding at a real **** poor place, along with a bunch of other things.
The following write-up addresses that **** poor ground and how to improve it.


Improving the Instrument Panel Ground

The ground point for the complete instrument cluster on your XJ or MJ is located up under the driver’s side dash. If you lay on your back and look up under there with a flashlight, without wearing a hat, you will see a black wire attached to a shiny piece of metal almost directly above the hood release ****. The screw will have either a ¼” or 5/16” head on it.

This ground point is responsible for handling the ground circuit for the following items: Dome lamps, Seatbelt and key warning, trans comfort switch, wiper switch, headlamp switch and delay module, fog lamp switch, cargo lamp switch, all instrument panel grounds and illumination, power windows and door locks, cruise control dump valve, and a few more things.

The problem is that where the ground point is located does not have a good contact with the chassis where the ground should be. The solution is simple.

Make up a jumper wire with #10 gauge wire about 10” long. On one end, crimp on a ¼” round wire terminal. On the other end, crimp on a 3/8” round wire terminal.

Remove the screw from the existing ground wire and attach the small terminal of your jumper so that the original wire and your new jumper share the same attaching point, one over the other.

Look above the driver’s side plastic kick panel just forward of the top of the hood release ****. You will see an 8mm stud there. Attach the large terminal end there with a washer and nut over it tightened securely.

**Special note for Comanche owners: Make your jumper wire 12” long and attach it on the driver’s side kick panel close to the fusebox on the 8mm stud.**


Revised 11-29-2011