Power windows do not work?

Tiny
JEFF HERMAN
  • MEMBER
  • 2011 CHEVROLET EXPRESS
  • 4.6L
  • V8
  • 2WD
  • AUTOMATIC
  • 150,000 MILES
Express 2500. No power to any of the wires to either the driver side or passenger side. I think the constant hot should be the heavy green wire to the driver. CB2 circuit breaker under the driver's seat is good but there isn't any power in or out of it. I'm suspecting an issue with the fuse block. My question, is there a fuse or relay I should check? The only thing labeled as having anything to do with the power windows is CB2.
Monday, September 4th, 2023 AT 9:18 PM

1 Reply

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 108,139 POSTS
Hi,

You are correct. The dark green wire is the power supply via the circuit breaker. However, for the circuit breaker to get power, the RAP relay (retained accessory power) needs to be activated. See pics 1 and 2 for the wiring schematic.

The primary on the relay is controlled by the body control module (BCM). The BCM sends power to pin 86 on the relay and pin 85 provides a ground path to energize the relay.

Once that happens, power that is always present on pin 30 is sent through pin 87 to the circuit breaker.

So, if you have no power at the circuit breaker, we need to check the RAP relay which is also under the seat.

I attached a pic of the fuse box below and highlighted the RAP relay. Remove it and switch it with a different one having the same part number. If there isn't one, here is a link that explains how to test a relay and the circuit.

Do this and let me know what you find.

Take care,

joe

See pics below.
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Monday, September 4th, 2023 AT 11:07 PM

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