acfortier Posted August 19, 2021 Share Posted August 19, 2021 Got an odd issue on my '91 that I can't see to figure out what's the cause of the issue. Originally, the wipers would work intermittently--if you put them on LO, they MAY actually move, but it's not at any speed I would consider LO. The washer pump seemed to also work intermittently. I do have intermittent wipers, but I've bypassed that module all together, so I've ruled that out as being the issue. Once the wiper motor is disconnected, the washer works without issue. As soon as you connect it again, nothing. I added a ground for the wiper motor, and cleaned the dash and driver's side inner fender grounds. Still nothing. Not sure what to try next? Link to comment Share on other sites More sharing options...
eaglescout526 Posted August 19, 2021 Share Posted August 19, 2021 Have you checked for any melted plugs or any resistance in the wires? Link to comment Share on other sites More sharing options...
acfortier Posted August 19, 2021 Author Share Posted August 19, 2021 No visible melted plugs. Haven't taken apart the steering column to see if there's anything wrong in there, but everything else is good. I haven't tested resistance in the wires, but I'm getting the correct voltage at the harness-side plug for the wiper motor. As soon as I connect the wiper motor, it goes haywire. I have no idea why connecting the wiper motor all of a sudden messes everything up. If I wiggle the plug, it may get better or worse (I actually was able to get them to rotate twice without stopping, usually it's just a split second movement then nothing), but I don't see anything wrong with it. Unless the new motor I purchased and spliced to the old plug is no good, I don't know what else it could be. Link to comment Share on other sites More sharing options...
eaglescout526 Posted August 19, 2021 Share Posted August 19, 2021 Definitely check for resistance everywhere including ground post to body on the MJ itself. Sure it shows you getting full 12v but as soon as it calls for a load, the voltage won’t be enough to meet the demand. Link to comment Share on other sites More sharing options...
jdog Posted August 19, 2021 Share Posted August 19, 2021 If you can set up a new ground from the wiper motor Link to comment Share on other sites More sharing options...
eaglescout526 Posted August 19, 2021 Share Posted August 19, 2021 Just now, jdog said: If you can set up a new ground from the wiper motor He’s done that in his build which still has me concerned about resistance in his wiring. Link to comment Share on other sites More sharing options...
jdog Posted August 19, 2021 Share Posted August 19, 2021 Ah then yeah it's time to break out the ohm meter and check those wires Link to comment Share on other sites More sharing options...
acfortier Posted August 20, 2021 Author Share Posted August 20, 2021 Well, got it all fixed up. The wiper motor I purchased from the parts store said it was for my '91, but it had a different plug on it with different colored wires. I attempted to splice the old plug onto the new motor, which obviously didn't work. Had a sneaking suspicion that the new motor was no good... So ended up looking up an '88 wiper motor, and it looked like the right one (and had the round plug like I have in the pictures). Picked it up, didn't have the plug in the box as you had to use the existing one, so I cut it off of the other motor and wire nutted it on to test... and viola. Worked without issue. I'm thinking I had a bad wire within in the motor, not really sure though. Anyways, all fixed up! Link to comment Share on other sites More sharing options...
jdog Posted August 20, 2021 Share Posted August 20, 2021 Glad to hear you got it fixed Link to comment Share on other sites More sharing options...
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