TR2/3/3A TR3 Wiper motor wiring and testing

[Joel Lester]

Hey guys! Doing a frame off restoration on my '58 TR3. Getting closer to getting ready to re-wire the entire car. In the mean time I've been finishing up most of the stuff in the engine bay. I cleaned up the wiper motor, painted it and put it all back together. I figured I'd try to see if the motor works or not so I grabbed a 12V battery and put neg on one terminal and pos on the other - sparks is all I got! LOL! Then realized the neg goes on the screw that holds the cover on - sparks again!!

I then looked back at the old pictures I took when taking this whole car apart and noticed a black ground wire that comes off the wiring harness and goes under one of the mounting bolts for the wiper motor. So maybe it's not working because I didn't ground to the car?? Looking for some guidance on how I can test this before I get the new wiring harness (there isn't an inch of wiring on the car now).

BTW... this car has never ran since I got it - it was a "barn find" of sorts. I've been working on this complete restoration for about a year and a half. It's really looking good but from time to time I need to reach out to you guys for some help!

Thanks in advance.

Joel

 

[Popeye]

These are not intuitively wired. The motor ground may be only used for the self-parking function.

Basic operation of these beasts: > General Tech - Lucas DR3A Two-Speed Wiper-motors <

https://mgaguru.com/mgtech/electric/pdf/2spd_dr3a2.pdf

Some info specific to your car here: > Refreshing and Wiring a TR3 Wiper Motor <

 

[DrEntropy]

These are not intuitively wired.

More like diabolically wired!

 

[Joel Lester]

Thanks for all of that incredibly useful information Mike. I really appreciate it! I think I'll wait until I get the wiring harness and get it all wired up like it should be and go from there.

Cheers!

Joel

 

[mt10flyer]

I think the TR-3 has a single speed wiper motor. By coincidence I just worked on mine. There are two spade posts on mine. One is for the 12v coming off the switch (mine is converted to neg Ground) and the other is ground. What you did should be a good test so the wiper motor may be fried. I would remove it and bench test it for verification.

 

[Popeye]

Let me know if you want my single speed wiper motor (I replaced it with a two speed.). It’s not been tested, but I took it apart and cleaned it and replaced the brushes. And I can’t vouch it fits in a TR3.