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TR2/3/3A Wiper motor hookup

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Jim_Stevens

Jim_Stevens

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This one has me going crazy:
Bench tested the motor, sat, last year. Self parking and the motor worked.
Hooked up the motor per the schematic. Picture attached.
Based on a previous posting here on the forum, I double-checked that the switch on the panel goes to ground.
E on the motor goes to ground, multiple paths.
Disconnected the BG wire from Terminal 2 and verified it goes to ground when the switch is pulled.
Mechanically disconnected the motor from the wipers in case it was binding
I have 12V at terminal 1, at the top of the motor where it goes to the arm, and (even though it is goes to ground through the switch) terminal 2. (Kirchhoff’s law doesn’t apply to Lucas, I guess.) And yet the motor doesn’t turn.

Any ideas? 61AE93C4-EC1F-4984-BA23-DF93829DEB68.jpg
Jim
TS44743L”O”
 
First of all, you've got it wired backwards (but that's not the only problem).
Terminal 1 should ground through the switch (BG), terminal 2 gets power from the fuse block (G). Check page 48a at https://drive.google.com/open?id=0B2H2NJt34OffNjQ4MTkyNjItZTVmYi00M2U2LWJhYWUtMjEyZDgxMzUyNzUw

If you are finding 12v on BG with the switch on, then there is a problem in the path through the switch to ground. You might look for the instrument panel ground wire where it connects to the control box and make sure it doesn't go hot with the switch on. Then I'm afraid you need to get access to the switch itself, so you can test (carefully) with the circuit complete. It's probably best to either insert something at the battery to limit current (in case of a short), or use something like a battery charger with inherently limited output current. I like to use old H4 headlight bulbs as a current limiting device.
 
Progress. My mistake on terminal numbering: terminal 1 is actually on the bottom, terminal 2 is on top, so I had it wired correctly. The progress just now was that I disconnected the BG wire and ran a wire from terminal 1 to ground directly, and the motor turned and self parked. So the issue is indeed at the switch. Thanks Randall. Will post when more progress made. Oh, and I’m using a fused small 12v battery rather than the car battery during this “testing phase”
 
Jim_Stevens said:
Progress. My mistake on terminal numbering: terminal 1 is actually on the bottom, terminal 2 is on top, so I had it wired correctly. The progress just now was that I disconnected the BG wire and ran a wire from terminal 1 to ground directly, and the motor turned and self parked. So the issue is indeed at the switch. Thanks Randall. Will post when more progress made. Oh, and I’m using a fused small 12v battery rather than the car battery during this “testing phase”
Click to expand...

Thanks again Randall— I went back into the dash panel and found the miswiring at the wiper switch. Corrected it to go to ground, and voila. And Kirchhoff proved right again. Humbled again.
 
Good. I'm glad you got it worked out, Jim. It's easy to get confused with all the different wiring schemes.
 
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