Rear defroster not working

[SnowDrifter]

Well..... I Noticed my rear defroster ain't working

Fuse under the hood has power
Rear cables have power when disconnected from the defrost tabs
But when connected to the tabs, voltage at said connectors drops to 0v. Not even 1-2v, friggin' 0.0v. Like... dammit....

Wiper is fine. Defrost, is not.

I reckon I need to start tracing wires and looking at connectors. Anyone have insight on junctions / plugs / ground / places to look? It's cold and snowing outside and I'm not much looking to rip apart my interior any more than I need to

 

[Doubeleive]

Well..... I Noticed my rear defroster ain't working

Fuse under the hood has power
Rear cables have power when disconnected from the defrost tabs
But when connected to the tabs, voltage at said connectors drops to 0v. Not even 1-2v, friggin' 0.0v. Like... dammit....

Wiper is fine. Defrost, is not.

I reckon I need to start tracing wires and looking at connectors. Anyone have insight on junctions / plugs / ground / places to look? It's cold and snowing outside and I'm not much looking to rip apart my interior any more than I need to

Remove the coiled wires at the glass, then check the 2 connectors on the glass for continuity, if no continuity then look for a break in the defrost wire on the glass and repair if possible.

 

[SnowDrifter]

Remove the coiled wires at the glass, then check the 2 connectors on the glass for continuity, if no continuity then look for a break in the defrost wire on the glass and repair if possible.

Glass is good

 

[George B]

Did you measure the resistance of the glass tracing?

 

[SnowDrifter]

Well

****
She'd dead, Jim
Gonna need both sides of the harness. Can I get a hand tracking down part numbers? My google-fu is weak on this one and I'm not turning anything up

 

[S33k3r]

Well

****
She'd dead, Jim
Gonna need both sides of the harness. Can I get a hand tracking down part numbers? My google-fu is weak on this one and I'm not turning anything up


View attachment 387859View attachment 387858

Are those connectors in a hatch wiring harness? I ask because it might be cheaper to buy a whole rear door. In many cases, people are just looking for the glass or the Escalade brake light; they leave behind a full hatch. People with the left-behind hatch tend to sell them cheap. You can steal the wiring and junk the hatch.

 

[Doubeleive]

Well

****
She'd dead, Jim
Gonna need both sides of the harness. Can I get a hand tracking down part numbers? My google-fu is weak on this one and I'm not turning anything up


View attachment 387859View attachment 387858

GMC

Find by Manufacturer GMC

connectorexperts.com

 

[Doubeleive]

maybe a junkyard also, you might have a poor ground in the mix somewhere also that shouldn't happen

 

[SnowDrifter]

Are those connectors in a hatch wiring harness? I ask because it might be cheaper to buy a whole rear door. In many cases, people are just looking for the glass or the Escalade brake light; they leave behind a full hatch. People with the left-behind hatch tend to sell them cheap. You can steal the wiring and junk the hatch.

Kind of
It's the hatch-to-body harness connector. Body side, by the hinge
Looks like there's a sub-harness that has the hatch side covered
But I cannot, for the life of me, find the chassis side

Liftgate Wiring Harness Extension 15173014 | GMPartsDirect.com

15173014 - Liftgate Wiring Harness Extension

www.gmpartsdirect.com

Grrr.... If this didn't interface with a weather seal, I'd just do my own harness with some beefier bits

 

[SnowDrifter]

maybe a junkyard also, you might have a poor ground in the mix somewhere also that shouldn't happen

Yeah I think I had some water intrusion that caused that to happen, unfortunately.