Wipers not working

2004 GMC YUKON
130,000 MILES • V8 • 2WD • AUTOMATIC
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HSOJXJOSH
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Hello. My Denali has an issue with the front wipers. The wipers will only work on the highest setting. All low to high inputs through the turn-signal/wiper switch do nothing, also the washer spray will not work when turning on via switch. I have replaced fuses and a relay for the wipers and washer, installed a new wiper service/turn signal, new wiper control board followed by a new wiper motor with another new control board, spliced on a replacement wiper motor connector, and tested wipers with a different BCM (without actually starting the vehicle) and I still have the same issue with no changes after any of these repair attempts. When the problem first appeared I also had no park for the wipers but that issue was corrected somehow along the way.

The problem presented itself after I installed a aftermarket stereo, I ran the switched voltage for the stereo from the wiper fuse inside the car. I'm not sure if something happened from that stereo install to cause this issue, but I have made sure that I didn't pinch any wires in the area the stereo is installed in. I have done a lot of wire continuity tests to check for breaks in most wires from the switch to the motor itself and haven't found any. Is there something I am overlooking? Any help or advice is greatly appreciated. Also if anyone can provide me with normal voltage and resistance readings at the motor connector it would help. Thank you in advance.
Jun 17, 2019 at 3:32 PM
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STRAILER
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Hello,

There is a relay, motor and switch not to much to go wrong. you said you replaced the module? Lets check the wiring by using this guide and the wiper wiring diagrams below:

https://www.2carpros.com/articles/how-to-check-wiring

Check out the diagrams (below). Please let us know what you find. We are interested to see what it is.
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Jun 18, 2019 at 7:24 PM
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HSOJXJOSH
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Hello. By module are you speaking of the wiper transmission/motor control pulse board? If so yes, one transmission swap and two different pulse boards. After posting this question I also swapped the fuse module inside the cabin and the one under the hood, still no luck.
I attempted checking the wiring, but not sure I am doing correctly. For resistance readings am I connecting one lead to wire at the motor harness and the other at the turn signal combo connector to the same wire?
While doing some wire voltage testing easier at the switch upon grounding one probe and the other to the blue wire, I have 12 volts at every setting expect the high setting to which I have no voltage, is that normal?
Also, earlier I tested voltage coming to switch from harness with a green, a yellow, and a black with white stripe wires: I had 12 volts at both green and yellow. I then tested continuity and found both green and yellow wires were grounding out. I traced it to the green wire at the BCM. Upon inspection of the BCM, I found a solder point touching both sides of a component I believe was a resistor. Anyway, I cut the traces and re traced the PCB which I thought would be the fix, but I have the same issue. Does the BCM need relearn possibly? I'm at a complete loss here. I'm sure doing wire testing, correctly, will be helpful. I appreciate your assistance.
Jun 19, 2019 at 11:37 AM
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HSOJXJOSH
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Also, where is the tan wire coming from the switch that grounds out? Thank you.
Jun 19, 2019 at 11:42 AM
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HSOJXJOSH
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I just had the car running and switched the headlights from Auto to the other two clockwise settings which worked fine, but when I turned it all the way counter clockwise to off the lights remained on. I then depressed the button that turns cabin lights off or on and the horn sounded twice. Are we likely looking at an electrical issue?
Jun 19, 2019 at 11:56 AM
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STRAILER
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The tan wire should be 0 resistance to ground and you should have 12 volts power at the yellow wire with the key on do you?
Jun 20, 2019 at 12:05 PM
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HSOJXJOSH
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Tan wire has continuity with ground and yellow wire is 12volts. Grey wire changes resistance readings when switching through wiper low to high. Blue wire has 12volts through all settings until switch is in high position.
Jun 22, 2019 at 2:34 PM
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HSOJXJOSH
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Hello. I was able to get the wipers to work correctly while testing with my multimeter. If i have my meter on the continuity setting with black lead to ground and red lead to the pink wire, everything works. I'm just not sure how this relays to what I need to do to the vehicle for the fix at the moment.
Jun 22, 2019 at 3:07 PM
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HSOJXJOSH
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Finally solved. The last fix was swapping out the motor pulse board. I think the real fix came from changing out fuse boxes. The schematics you provided were very helpful. Thank you.
Jun 22, 2019 at 7:13 PM
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Glad you could get it fixed, that kind of problem can be tough. Please use 2CarPros anytime we are here to help.
Jun 23, 2019 at 12:32 PM