Windshield Wiper Switch Shorting?

Noticed today that the circuit breaker on my windshield wiper switch cycles on and off even with the switch in the off position. OK, the switch may be bad but what's strange is this happens with the ignition in the off position. I thought the wiper motor only operates if the ignition switch is turned on. I think the problem started when one wiper somehow got out of position and pushed against the cowl. It couldn't complete the cycle and just stuck there until I shut the wipers off. Could it be the motor is still trying to park itself? The motor doesn't turn at all at this point. Any ideas on what's going on?

 

studied the FSM
more confused now
try unplugging the suspect motor and see if that stops the circuit breaker
you are correct that the power is fed thru the ignition switch
so maybe it is trying to "park" and isn't able

 

beeser not sure about the circuit, but it's not uncommon for the passenger wiper to lock up. Is that what happened?

For fun, here's a related thread if that's the case:
http://www.earlycj5.com/forums/showthread.php?t=5513&highlight=wiper+linkage

HTH!!
-Alan

 

Alan - Good link. I'll check everything out tomorrow. I seem to recall that the windshield frame sheet metal was bent near one of the posts. What started the problem was the driver's side wiper turned got out of sync and ended up pushing against the cowl. I have no idea what caused it. I shut the wipers off and removed the offending wiper and now, nothing moves when turning the switch and the circuit breaker cycles on and off. As I mentioned before, it's strange that this cycling happens even with the ignition switch off.

 

Yep, the linkage was indeed locked and the windshield frame around the passenger side post was bent. I disconnected the wiper motor from the linkage and it runs correctly at both speeds. It's still a mystery why the breaker would cycle on and off especially after the wiper and ignition switch were both turned off. It doesn't do it now though. So, I should be able to fix the linkage and straighten the sheet metal and be good to go thanks to the above suggestions. Good goin' guys!

 

Even if the switch is off, the motor will try to park. The on-off switch and the park switch are in parallel - they both need to be open for the motor to stop.

 

The motor on mine stops at different positions in the rotation. Does that mean that the park lead is either not making proper contact or the switch itself is bad. The FSM shows the park wire is black. Correct?

 

Really strange, after hooking the linkage back up and testing that everything was working OK the circuit breaker started cycling on and off again without the ignition and wiper switch turned on. Disconnected the black lead (park) and nothing changed. Then I disconnected the linkage and the circuit breaker cycling stopped. Anybody have any clues as to what's happening? I might still have some binding in the linkage but without any switches being turned on it doesn't make sense why there is even any power going into the breaker.

 

I know how the circuit works in a '72 and later; I presume the earlier motors are the same.

Basically you have a hot wire that goes to the motor all the time. There are two ways to connect the motor windings, providing a fast and slow speed. Each of these circuits is grounded through the two contacts on the wiper switch.

The park switch is in parallel with the high-speed motor ground on the wiper switch. The park switch goes to ground through the windshield frame - thus you only have three wires (hot, low speed ground, high speed ground) that go to the motor. If the motor ground lead is disconnected or the the windshield does not have a proper ground, the park function will not work. On the intermediate windshield, there's a black lead under the motor cover that goes from the motor to the windshield frame - this is the ground for the park switch.

You can reverse the polarity on everything and the circuit will still work, ie make the switch side hot and have a common ground. This requires that you run a separate hot wire to the park switch though. I think some rewired Jeeps may be set up this way.

I'd have to see the circuit diagram from your year CJ to be more certain.

hth

 

Eureka! What I thought was the wiper switch circuit breaker tripping was actually the light switch circuit breaker. A wire on top one of the terminals shorted. While fooling around with the wires on the wiper switch I must have moved the shorted wire enough to eliminate the problem temporarily. Looks like I had two problems at the same time.

Thanks timgr for the wiper switch parking analysis. I'll get back into this problem as soon as the light switch problem is resolved.