windshield wiper troubleshooting

[oldjeeplady]

Hey all - I have some questions about troubleshooting a windshield wiper motor and switch. This is for a 79 CJ7 that we got a couple weeks ago to make sure we would have a CJ ready for the CO trail ride.

I set up bench testing based on what I have read in the 79 FSM and the schematics i have found. This is a two speed motor with four wires out and three to a plug. (Red, green, black to the plug, and blue w/trace is park I think) Using a 10A protected hot lead and solid grounding (to the battery neg) the motor case, I was able to get the motor to run in both speeds and stop, but I cannot get the park function to work. I don't know if the motor is bad, the switch is bad or I am testing it wrong. Should I also run a wire from the battery neg (ground) to the switch case? I have not seen that the switch is grounded in the schematic, but it IS normally mounted in the dash which is sometimes used as a case ground. I am attempting a bench test. Any insight would be appreciated.
Some pics:

The switch



The switch with the motor plug and the hot lead. The empty terminal is where I connected the park wire.



All connected:



Maybe I am expecting the park function to work on the bench and it actually has to be installed with the linkage. That would be my next step to try, but even my small hands don't fit up behind the dash easy. The front seats are still installed and I almost got myself stuck trying to contort by body to reach and see what I was doing - next time I will be sure to have my cell phone. Thanks!

 

[oldjeeplady]

OK I was reading the test procedure again and found some things to try. This is without using the switch.... From the FSM:

"With the wiper blades in a position other than park, connect a jumper between terminals 1 and B. The wiper blades should run on low speed and stop in the park position. If the motor does not run after making the jumper connection, there is an open in the black wire, a defective internal motor connection, a misaligned or damaged set of contact points or a bad connection through the park point set to the low speed brush. If the wiper motor runs but does not park, the cam on the drive gear is not sufficiently breaking the contact points...."

I will try the jumper, see what happens and do the rest. This should tell me if the motor works independant of the switch.

Thanks for listening... I talk to myself a lot while my better half is on the road. Sometimes I just have write it down to understand...