2005 Tahoe rear defogger not working

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Opus62

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Hi guys and gals.

I have a problem with my 2005 Tahoe rear window defogger. The wires are connected but no power there. The mirrors defog/defrost quite nicely but nothing at the back. I have not started much diagnostics yet so I am looking for any info regarding common issues that others may have had.
:hmmm2:
 

JochenWoern

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Hi guys and gals.

I have a problem with my 2005 Tahoe rear window defogger. The wires are connected but no power there. The mirrors defog/defrost quite nicely but nothing at the back. I have not started much diagnostics yet so I am looking for any info regarding common issues that others may have had.
:hmmm2:

Having exactly the same issue and could never figure out what was wrong.

Living in Northern CA, I accepted the fact and decided to live with it as I never get ice on my windows.
 

Larryjb

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Sorry to resurrect an old post, but did you every find the problem?

I seem to have 12V when I remove the plug, but it drops to 0 as soon as I connect it to the grid. I'm suspecting a bad connection in the wire leading up to the plug, but I cannot find any wiring diagrams that show the routing of this wire.
 

Yates_III

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Barn doors or Lift gate? Asking for troubleshooting reasons. If you have a lift gate w/ a wiper, see if the wiper comes on.

I had the same problem where my rear defrost and my rear wiper wouldn't work. Ended up being the connector plug. Cleaned the connections with electrical contact cleaner, plugged the connector back up and haven't had an issue since.
 
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Larryjb

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Lift gate. Thanks Yates. I'll check into that. I didn't realize there was an actual plug in the lift gate.
 

Yates_III

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No problem Larryjb. There is a rubber boot that runs from the lift gate to the body of the truck. You can pull the trim panel that holds up the headliner, GENTLY pull down headliner to access the plug assembly. Spray it with the cleaner and inspect for broken connections and hopefully that clears up your issue.

Good luck!
 

Larryjb

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Thanks again Yates. I thought the connector was actually in the liftgate and was about to look there. I'll look behind the headliner and see tonight.
 

Larryjb

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I found the connector, and the defog wire in the connector was badly burned. Unfortunately, I don't think that's the end of the trouble. When I put the volt meter on the good end of the wire, I still only got 6V which means there is a bad connection further up the line.

So, what is the next connector up the line?
 

Yates_III

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I was hoping that wasn't the case for you...sorry to hear that.

I will have to look on the wiring diagram to see where the next connections are upstream from that rear connector.

Do you have rear HVAC controls and/or moon roof?
 

Larryjb

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I do have rear HVAC contols and moon roof.

Are you using the wiring diagrams from the FSM?
 

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