Wiper Motor Replaced/Now Worse!!

I just replaced the wiper motor on my '99 Suburban because the wipers would only work intermittently. I put in a new motor and it has a mind of it's own! It only works on high (squirts washer fluid as well) and when you push to wash (but the wash won't stop until you flip the switch a couple times).

At least the old motor would work right (just not all the time). When it would not work you could hear an electrical hum as if it were trying to work.

This is the second motor I have tried with the same results. A remanufactured one and now a brand new one.

Has anyone experienced this problem or have any suggestions?

I'm in Germany, so the local technical help isn't very helpful.

Thanks!

Rob

try running a ground from the motor to the firewall on clean metal and see what happens it worked for my truck. hope this helps.

Thanks. I did a search on another Chevy Forum that suggested cleaning the contacts on the old motor, so I did that and it works (for now). If/when it stops working again I'll try putting back in one of the other new motors and running a ground strap to see if that works. I'm pretty quick at replacing the motors now!

It really seems odd that I can get my old motor to work, but both new motors freak out the same way. It makes me think they are wired differently or something. Not having a good ground can cause some strange things though. Thanks for the reply. I'll let you know if it does the trick.

Rob

did you replace the module on the end of the wiper motor if not i highly suggest doing so . chevy tech wes

If you know how to solder then I would go and resolder all the solder joints on the circuit board. From the factory they had weak solder joints and would cause intermittedent problems. If not then like the guy above said did you replace this part or the motor itself?

So far so good with the original motor. Just cleaning the metal residue off the wheel inside has done the trick so far. It's been through several good rains and everything still works like a charm. I've even stopped holding my breath when I turn them on now. I still have the two "new" ones in boxes as back up. I do need to learn to solder though! Thanks again.

Rob

Well, 6 months of no issues with the original wiper motor after cleaning it was pretty good.  It gave up the ghost entirely so I re-installed one of the new ones with a ground wire from the motor to a ground point on the firewall.  I sanded the paint off where the wire is mounted to the motor.  It still does the exact same thing.  It still seems to me that the circuit boards must be wired differently or something.
 
Which part are you referring to as the module on the end of the wiper motor?  I see the motor(canister part), circuit board, and the housing itself with the gear in it.  Each time I have searched I have not found a listing for just a module. 
 
I noticed that my original circuit board has the word "Pulse" on the connector where the wire from the vehicle connects to the circuit board.  Both of the new ones have STD in that area.  (Presumably meaning Standard)
 
Any experts out there know if there are different versions of circuit board?  Each time I ordered a new motor there was only one part number offered.
 
As a band aid fix so my wife can drive it (it's been raining a lot here in Germany lately) I disconnected the washer pump.  That way it doesn't constantly spray washer fluid.  She can either hold the washer button to get them to wipe or turn them on high.  She just has to turn them off at just the right time so they don't stop midway up.
 
Any other suggestions are appreciated.  In the meantime I will look for someone that knows how to solder.   
 
Thanks,
Rob

New Update:  I had a friend solder the original circuit board and I reinstalled the original unit.  It worked perfectly!... For about a day :(  Now it's back to the same intermittent, "work when it wants to" thing.  I did go ahead and open up the two "new" motors and the circuit boards are entirely different!  No wonder the things freak out instead of working properly.  Obviously ordering another "new" motor isn't going to be the answer.  I guess I'll go back to the jury rigged method.  This is very, very frustrating!

Well, I've had the original circuit board re-soldered and swapped the motor for a new one and it still does the same thing.
 
I have to find a way to order the correct replacement wiper motor!  I need to find one that has the black wiring connector that says "Pulse" on it, but that is proving more difficult than I thought.  Chevrolet dealerships ask for the VIN and then say there is only one part number for that application and the one I ordered is it.  By chance I was on autozone.com the other day ordering brake parts (I'm in Germany) and happened to look for a wiper motor.  At least they list different applications such as "black wiring", "with delay", "with intermittent wipers", etc.  Now it's just making sure that I get the right one instead of ordering a THIRD one that doesn't work...
 
Rob