Wiper bench test…on car

[TimDart]

Guys my wipers don’t work. I have the procedure for bench testing the motor. Is there any reason why I can’t do the bench test with the wiper motor still attached? I’d unplug the bulkhead connection for the wipers and test it on the disconnected battery

this test;
Bench testing procedure.


Test #1(Hi speed)


Connect jumper wire from motor case to battery ground.
Connect second jumper wire from batterypositive to BROWN lead.
Motor should run hi speed continuously.


Test #2 (Lo speed)


Connect jumper wire from motor case to battery ground.
Connect jumper wire from GREEN wire to battery ground.
Join BROWN and RED wires together and connect a jumper wire from battery positive to them.
Motor should run at slower speed.

 

[halifaxhops]

Should work fine.

 

[TimDart]

I’ll give it a go then

 

[TimDart]

Ah well. Didn’t work. New project, then.
However I did do a voltage test at the firewall connector. The main feed wires (Brown, red) to the wiper motor show battery voltage With switch turned on. I cleaned everything at the connector, reconnected and then checked voltage again at the two power wires. Somewhat amazed to find just 3.8 volts showing.
I can’t belivee that such a voltage drop could be possible given that the connections are clean and feel tight at the connector.

 

[cudamark]

What year and model? 2 speed? 3 speed? variable speed? I'd first check the ground strap to make sure it's not corroded or has a bad connection of some sort.

 

[TimDart]

Yes, quite. It’s a ‘67 Coronet and I believe it’s a two speed (off, on, on 2), the earth strap is intact but from what I’ve read around today, running grounds from the motor and the switch may be required.

 

[CRUZE 418]

Ballast resister?

 

[Hemiorangeswinger]

My money is on a seized wiper pivot. Unhook the wiper motor under the dash and see if the pivots move freely.

 

[CRUZE 418]

This was over a month ago, did the OP find the problem yet? It has to be one of 5 things, power, ballast resister, motor, pivot, or ground. I guess it could be one other thing, my Dart had a 3-speed motor in a 2 -speed system, linkage appeared to be attached, but wasn't, because they are incompatible. We have no pictures.