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Mike S.
Mike S., ASE Certified Technician
Category: GMC
Satisfied Customers: 7568
Experience:  GMC N.A.I.S.E. Certified Auto-Mechanic
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My radio and front power windows aren't working. ive checked

Customer Question

my radio and front power windows aren't working. ive checked the fuses I believe correctly and they all seem fine. maybe there's another fuse box?
JA: Have you checked the fuses?
Customer: yes, if I checked the correct ones...they were fine
JA: Tell me a bit more about what's going on so he can help you best.
Customer: the radio displays time and will eject a cd, but no sound or radio function is working, the front power windows will not raise or lower. back windows are fine, everything else is working properly with the car
JA: Are you hoping to fix this yourself?
Customer: yes
JA: Great! What have you tried so far?
Customer: did you read my previous text? ive checked the fuses - at least as far as which ones I know to check from the manual
JA: Is there anything else the GMC Mechanic should be aware of about your GMC?
Customer: these problems started after i recently changed the battery
JA: OK. Got it. I'm sending you to a secure page on JustAnswer so you can place the $5 fully-refundable deposit now. While you're filling out that form, I'll tell the GMC Mechanic about your situation and then connect you two.
Submitted: 1 year ago.
Category: GMC
Expert:  Don - Mo Lurch replied 1 year ago.


Customer: replied 1 year ago.
2001 GMC Yukon 1500
Expert:  Mike S. replied 1 year ago.

For the radio, it's most likely the "RDO 1" fuse, located in the left side of dash fuse block and the "radio" fuse, located in the underhood fuse block.

For the front power windows, wait I see the radio and power windows is powered only when the RAP relay is energized, so that may be the problem.

Anyhow, the power windows are fed from circuit breakers and relays. give me a second on that RAP relay.

Expert:  Mike S. replied 1 year ago.

Check the "IGN B" fuse under the hood.

Expert:  Mike S. replied 1 year ago.

Also check the "RAP" fuse, under the hood.

Customer: replied 1 year ago.
Checked the RAP 1 and RAP 2 fuse as well as the IGN b fuse and all were fine. Where is the RAP relay, is that different from the RAP fuse?
Expert:  Mike S. replied 1 year ago.

Yes, the relay is different from a fuse. It should be located in the fuse box lower left side of dash.

Customer: replied 1 year ago.
RAP #1 on the diagram is a black cube, seemingly with multiple fuses within. Is this the relay and if so, how do I test it? It seemed to almost not even budge when i tried to loosen it.
Customer: replied 1 year ago.
Okay, black cube is the relay. Still need to know how to test it. Thanks
Expert:  Mike S. replied 1 year ago.

There are several things to try. You could try swapping it with another relay of the same type that is working and see if it works then and also that the other item don't work now. You could see if maybe there is a spare in the relay box. Usually relays click when they are powered up, so you could touch it with your finger and feel if it clicks when it is powered, but then again that only check 1/2 of the circuit. Next would be to remove he relay and test for voltages in the socket.

I don't know if I asked previously, but do you have a voltmeter or at least a 12 volt test light?

Customer: replied 1 year ago.
I do have a voltmeter. I replaced the RAP Relay (thinking it had to be the problem since all fuses checked), but the problem still persists...wasn't the relay.
Expert:  Mike S. replied 1 year ago.

A good way to tell if that relay is working is testing if those fuses have voltage, cause from what I read they only have power when that RAP relay is activated.

Expert:  Mike S. replied 1 year ago.

Not the RAP fuse though, that powers that RAP relay, I mean the fuses "RDO 1", "Radio" and the "PWR WDO" circuit breaker.

Expert:  Mike S. replied 1 year ago.

Then again with the RAP relay not energized the radio and power windows gets it's voltage from the ignition switch and the "IGN B" fuse, so check it as well but you would have mentioned a lot of more things other than that not working if that were blown.

Customer: replied 1 year ago.
I installed the new RAP Relay and still not working, not sure what I should do now.
Expert:  Mike S. replied 1 year ago.

Ok, that doesn't mean the rap is working, cause if it's not getting voltage it won't work. Remove the relay and make sure it is getting power in the socket. First check the "IGN B" fuse and use the voltmeter and test both sides of the fuse. Plus, test both sides of those other fuses, the "RDO 1", "Radio" and the "PWR WDO" circuit breaker you can usually just remove it and test for power it it's socket. Test with key off and key on.

Customer: replied 1 year ago.
Okay, so we have the hot/neutral (red and black) prongs/probes....Do I I Just use the red to see if it's getting juice or do I use both probes?
Expert:  Mike S. replied 1 year ago.

You have to use both, ground the black (ground) probe to a good clean metal surface or the battery negative post if it will reach and use the red (positive) probe for testing for voltage. There is no neutral probe.

Customer: replied 1 year ago.
Okay, I'll have to try that this week. Was out of town this weekend.
Expert:  Mike S. replied 1 year ago.

ok, let me know when you have tried that.

Expert:  Mike S. replied 1 year ago.

Did that answer your question? If so, kindly leave me a positive rating, so I get credit. If you have any more questions, go ahead and ask.