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Rear Wiper "thumps" and doesn't turn

4K views 21 replies 6 participants last post by  MrHolland 
#1 ·
My rear wiper motor "thumps" but doesn't turn. When I say thumps it makes that sort of sound.

The pump works and gets fluid but the wiper doesn't turn.

I got another pump from salvage and hooked it up and it does the same thing.

I know it's possible I have 2 bad motors but what are the odds? Is there anything else I should check?

I checked the connector and am getting 12v on/off with the switch, the pump works so the only thing left if the motor, right?

I tried to rotate each motor with pliers the arm hooked up but it won't budge. I think they are both frozen and bad.

Any other thoughts?
 
#2 ·
BlueOvalKid said:
My rear wiper motor "thumps" but doesn't turn. When I say thumps it makes that sort of sound. The pump works and gets fluid but the wiper doesn't turn. I got another pump from salvage and hooked it up and it does the same thing. I know it's possible I have 2 bad motors but what are the odds? Is there anything else I should check? I checked the connector and am getting 12v on/off with the switch, the pump works so the only thing left if the motor, right? I tried to rotate each motor with pliers the arm hooked up but it won't budge. I think they are both frozen and bad. Any other thoughts?
Do you have a multi meter if yes check for 12 volt at the harness

If you get power then the motors are bad
 
#3 ·
Ok, I have tried 3 different motors and all behave exactly the same.

I have 11.8v on the supply wire and a good ground at the connector.

Turn the wiper switch to 1 or 2 and the voltage drops to ~ 7v. It seems like I have a voltage issue.

The pump works just fine and squirts fluid.

I have checked the 3 hatch switches and they all seem to be fine and give the proper "open" indication if I disconnect them.

Do I have a bad switch? Is there something else I'm overlooking?
 
#4 ·
BlueOvalKid said:
Ok, I have tried 3 different motors and all behave exactly the same. I have 11.8v on the supply wire and a good ground at the connector. Turn the wiper switch to 1 or 2 and the voltage drops to ~ 7v. It seems like I have a voltage issue. The pump works just fine and squirts fluid. I have checked the 3 hatch switches and they all seem to be fine and give the proper "open" indication if I disconnect them. Do I have a bad switch? Is there something else I'm overlooking?
Replace the switch as that sounds like the culprit
 
#6 ·
Any other ideas?

One other thing that I just found out, due to winter weather, is that my rear defroster also does not melt the snow. The switch lights up and cycles after a few minutes but does nothing to heat the glass and melt the snow/ice.

Are these related?
 
#7 ·
BlueOvalKid said:
Any other ideas? One other thing that I just found out, due to winter weather, is that my rear defroster also does not melt the snow. The switch lights up and cycles after a few minutes but does nothing to heat the glass and melt the snow/ice. Are these related?
That sounds like a loose ground as the rear defroster has to have a solid ground to work
Let me check my service manual and see where the ground is for the rear defroster
 
#12 ·
pmartell12 said:
mine thumps as well,,, occasionally it will do a half sweep, then stop.... when i open the glass, it returns to it's "closed" position.... is it a sensor for if the glass is open?
There is a sensor that tells the tbc that the door or window is open my guess it also works the wiper as mine goes into park position when I open either(window or hatch)
 
#14 ·
Espritv8 said:
Yep checked that, but it doesn't seem to be the problem. I'm thinking a bad ground, but don't know where to look at first. Defrost is not working either.
Both not working is surely a ground issue

There is a splice pack behind the right rear quarter panel

The ground point is also behind the same quarter panel

Check both and see if the issue goes away

Also check the battery ground cable as it can also cause some crazy stuff
 
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