Rear Wiper Motor - Replaced but no luck

[Micav]

Tis the season, I finally spent a few dollars on myself to fix up a couple of little items on my 2002 Yukon XL. Now all is sweet except the rear wiper. Still can't figure that out.

Problem. Does not work. When you turn it on, you can hear the motor 'trying' to do something. Tried to help by manually moving it, but no help. I assumed it was the motor.

I replaced the motor yesterday and is still does the same thing. The only exception....with a 'helping hand' I can get it to actuate VERY slowly for one pass.

Is there a relay or something that I am missing? With the new motor, I did remove the wiper arm and ran the motor just to see if ther was too much tension on the arm. It didn't help. The same thing. It just seems that the power getting to it is very weak.

Also, not sure if this is related. But I can't get the rear or mirror defrosts to work. The light on the control turns on, but does not defrost. I have checked the fuses and changed the rear defrost relay in the fuse center under the hood.

Any suggests are welcome. Sorry for the long post. Thanks for the help!!!

 

[Old Goat]

Micav,
This may help. 2002 Yukon rear wiper schematic.
Just a thought, try grounding the rear door body with a good jumper wire to see if it's a poor ground problem.
Charles

 

[hoemeup]

Rear Windshield wiper no go

I have the exact same problem. The rear window wiper does not work and the defrost won't work. Please let me know if you found the solution. I have an 03 Tahoe....Thanks

 

[shadow]

Same problem with my '00 Tahoe 5.3

Was gonna try to get to it this weekend.

Was it easy to get to the motor? Any trouble getting the interior panel off?

I do know that my Tahoe has been sensitive to electrical issues, I think these trucks need to have all the ground connections really clean and secure.

Old Goat, do you have an exploded view of the wiper motor motor assm.?

Regards

 

[Rivieraracing]

Just a thought, I think that there is some sort of switch or sensor in the latch for the rear window at turns off the rear defroster and rear wiper whenever just the window is opened up, your problem may be there.

 

[Rivieraracing]

Just a thought, I think that there is some sort of switch or sensor in the latch for the rear window that turns off the rear defroster and rear wiper whenever just the window is opened up, your problem may be there.

 

[hoemeup]

Good thought

I did not think about that...I will have to look into it....thanks

 

[warnergt]

Has anybody solved this? I think I have the same problem in my 2002 Yukon XL. I saw a post somewhere suggesting that washer fluid could leak onto a connector near the back gate causing the connector to corrode and become a bad connection.

 

[prowlingbear]

I just pulled the motor out of my rear door. Pretty simple job except that you have to open the rear window and pop two plastic rivets next to the window latch before you remove the interior panels. The interior panels pop off with a screw driver quite easily and the motor comes out with just a couple of bolts. The replacement looks easy enough, and a rebuilt motor is looking like it will cost $80-100.

However, now that I saw the post about the grounding issue, I am going to reconnect the motor to the power plug, ground the motor well to the vehicle and see if it is actually the motor that has gone bad, or a bad ground on the door to the vehicle.

More to come in the morning.

 

[warnergt]

I checked the voltage at the motor to see if I had some kind of grounding or connector problem. The voltage looked good. So, I replaced the motor. It works great now.

I couldn't get the two plastic rivets out without breaking them. However, I did find a nearly exact replacement here:
Push-Type Clip

 

[prowlingbear]

I tried grounding the motor with the switch on this morning and the motor did not do anything. I am going to check the ground wire by the passenger rear speaker and power to the plug as you did, and if they all check out, I will order the motor. The ground appears to check out, I have good voltage to the plug, and I used a 12v Charger to put power into the motor itself on the two wires that showed good voltage on the plug end, and the motor didn't even click or move, so I am assuming it is a bad motor.

Did you buy a rebuilt or new?

Thanks for the tip on the connectors, I had to break them both as well.

 

[warnergt]

Applying power to the motor is not enough to make it work. There are four wires going to the motor:
1) +12V
2) Ground
3) Control signal (I think this pulses or something to tell the motor to wipe)
4) Inhibit signal (signal to tell motor to park if back door or window are opened).

After a lot of Googling, I don't believe that bad grounds or bad connectors are a common problem here. I only found one or two references to that problem. Odds are your motor is bad as mine was.

I bought a new motor. It was about $175.

 

[prowlingbear]

Warner I think you are correct about the power in, but my meter showed 12V on two of the leads in, so I applied power to both of them on the motor with a jumper wire and grounded the motor and the other two leads, and the motor did not react at all. So I think you are correct, it is a bad motor.

I have ordered a new one, and we will see if it does the job.

Thanks for the input. I will confirm if it works.

Best,

 

[prowlingbear]

Well the good news was I found a new rear wiper motor for $60. The bad news is there must be a switch, a short or a ground that is not working as nothing happened when I put it in and turned on the switch.

Any ideas of where to start?

I printed off the Schematic posted by Old Goat, (Thank You), and I am going to study it a bit to try to figure out where to go from here. Just to check to see if the new motor is good, it appears that if I run hot in and ground the motor body, shouldn't the motor turn on?

Still hoping one of the Tahoe tech guys might have an idea of what else might be wrong?

 

[Crazywelder72]

any luck yet?

i just got around to replacing the rear wiper motor in my 02 Tahoe. the motor still clicks and struggles, can barley work with manual assistance. as a matter of fact i removed the wiper arm completely and it was struggling and clicking. when in the on position (either 1 or 2) it would struggle then return to the "home" position without reason. is there any chance the module that attaches to the motor is the problem? napa dosnt sell that part. the window interlock works, i haven't checked the ground yet but i will tomorrow. any other ideas??/

 

[gmchead]

Had the same problem ...put a ground wire from the motor housing to bolt on door fixed !!!

 

[Signpost]

Had the same problem ...put a ground wire from the motor housing to bolt on door fixed !!!

I just did the same thing on mine, and fixed it as well.

 

[clkelley]

Others having this issue may want to try to remove the loom surrounding the wiring harness that goes through the door/hatch jam into the truck, at the top of the hatch. I would bet that there is a wire or two smashed or broken there in some way.

 

[tonymac617]

PS: on those clips....you need to push the pin in the middle down to remove them. Then when replacing them, pull it up out of the clip then push flush to secure the clip back into place when your finished.

 

[badvwg]

The harness under the rubber boot is your issue. This same harness going bad (overheats, melts robbing you of power and ground) will also cause your rear defroster to quit working. Ask me how I know! I replaced the two melted wires, and both items began to work!