bench testing a wiper motor

[Wayne67vert]

I'm trying to bench test the wiper motor on my '68 Alpine. If I'm reading the wiring diagram correctly I should hook the 12 volt power to the red wire and the ground to the black attached to the case. Then I should be able to connect either of the other 2 wire to the power wire to make the motor spin. I did this and got nothing but hot wires. I think the motor is bad.
Am I correct ?

 

[dwolff706]

don't give up without opening the case and checking the internals.
Search the forum for "wiper grease" and should find some helpful insights. I have mine on the bench as well but it works after cleaning and lubrication. Dave

 

[65sunbeam]

Hope you didn't burn up your wiper motor!
Here are the connections to test a Sunbeam two speed wiper motor out of the car and sitting on the bench.
Peel back the gray plastic sleeving to see the unfaded wire color codes.

The black ground wire goes to negative 12 volts.
Green goes to positive 12 volts.
Red/green and ground wire together gives high speed.
Red/green and brown/green and ground wire together gives low speed.

If motor still does not work, take apart the wiper gear box and remove all the gears and clean off the thick grease and relube. The old grease will harden and lock up the gear sets.

 

[Wayne67vert]

Thanks Eric, I'll give that a try.
Wayne

 

[Bill Blue]

Also check the wiring. My motor would not run. I found that a wire had been pulled around a sharp corner and after all these years, the insulation had been eaten through. Simply relocated the wire so it was no longer in contact with metal, added a dab of electrical tape and all was well. But yes, the grease dries, gets very hard and becomes a problem.

Bill

 

[Wayne67vert]

Thanks Eric, my motor runs.

 

[phyrman]

I used service back East to rebuild mine Will find the name somewhere.......
its a Jaguar repair place.......... $275 if I remember correctly ........

 

[Gary T]

I had my wiper motor rebuilt by East Coast Jaguar and they did a great job.

 

[sunalp]

This is great information. I kinda figured it out on my bench as I have a power supply there
and just trial and error worked out to make it run. I do have a problem with my wiper motor
installed. It runs fine, both speeds ( SV), but when driving the car it will start by itself and you can't
turn it off. The wiring is fine ( all new) but this keeps happening, so my motor is disconnected.

Anyone have an idea why this occurs? I've had the same issue on two different cars.

Cheers!
Steve

 

[Wayne67vert]

So, when I reassemble the cable, it seems to be binding and the motor doesn't turn. The pipe the cable goes through is bent.
More work to do!
Wayne

 

[Bill Blue]

So, when I reassemble the cable, it seems to be binding and the motor doesn't turn. The pipe the cable goes through is bent.
More work to do!
Wayne

The pipe has to be bent in order for everything to line up. Be sure the bends are gentle. Also clean (as best you can) the inside of the pipe operating cable and re-grease.
Bill

 

[junkman]

Sounds like your stop wire is broken and rattles loose underway Steve, I would start there.
Jeff

 

[sunalp]

Thanks Jeff! I'll have a look.
Cheers!
Steve

 

[sunalp]

Oh, yeah.....which one is the stop wire? I know there's the power and the two speeds.
Is it an internal wire?

 

[Tom H]

It's the little wire coming out of the motor near the gearbox that connects to a terminal on top of the gearbox. Normally that wire gets grounded by a contact inside the gearbox to run the wipers to the Parked position. If that wire is not connected and is dangling, every time it contacts ground the motor runs. Maybe it's still connected and some other ground wire dangles and contacts that terminal.

 

[sunalp]

Thanks Tom,

I'll take a look!
Cheers!
Steve