rear defrost not working

[KEEBZ489]

2005 trailblazer , mirrors heat up when I hit the defrost button , but nothing to the back window. I pulled the trim and power going to the liftgate module is okay , the lines on the glass all show continuity when tested , now when I went to test the fuse there was no power , then I realized that the fuse might only be powered when the relay clicks on. stupid me pushed the tester in to hard and now the fuse is loose.

is the relay in the liftgate module itself ? I assume the climate control unit is working correctly since the mirrors heat up.

any ideas on what to test ?

 

[Mooseman]

I believe so and also realize one thing is that if the glass or liftgate are open, it may cut power off to the grid, same as it does for the wiper. Not 100% certain of that but a definite possibility when checking.

Also check the wires going through the grommet. You have to actually pull on the wires as sometimes just the copper inside breaks leaving the plastic covering intact.

 

[KEEBZ489]

interesting , I will double check with the tailgate closed. if still no power at the fuse I will swap the LGM. the wire through the grommet are all good , fisrt thing I checked for was continuity on both sides of the grommet

 

[KEEBZ489]

SOLVED keep playing with wires last night when plugging the white harness in the LGM I seen the contact for the large orange wire was black , not silver like the rest. tried the defrost again and had power to the grid ! I took the connecter apart and cleaned it best I can and bent the little contact so it has a tighter grip on the male prong of the LGM , little dielectric grease and good to go. I have to search where the ground for the grid comes from , I suspect it may have been the cause from the excessive heat and frying of the 12+ connection. also the defrost does work with the tailgate up , at least on my 05 EXT , the hatch glass I did not check.