tailgate glass won't open

[roy c]

Any idea's on why the tailgate glass won't open with the key, but does
with the interior switch?

 

[89Suburban]

I believe there is a switch in there hooked to the key lock, inside that tailgate. Like, separate from the actual key lock.

 

[bucket]

The contacts in the key switch are probably dirty from lack of use. Mine has this problem since I hardly ever roll down the window anymore (glass needs a new sash) and I need to investigate exactly how to repair it.

 

[roy c]

Do you feel a new key cylinder might cure it i sprayed WD 40 but n/g
it went bad sudden with no sign or nothing

 

[bucket]

Do you feel a new key cylinder might cure it i sprayed WD 40 but n/g
it went bad sudden with no sign or nothing

I don't think so, I replaced it with a new one about 6 or 7 years ago. I'm going to start by inspecting the plug on the backside, and the wiring in the tailgate. I don't remember exactly how the switch part is attached to the cylinder.

 

[89Suburban]

So the key lock cylinder itself is wired to operate it then.

 

[bucket]

I took a look at one of my spare lock cylinders. At the back of the cylinder, there is a little contact switch doohicky that snaps into the cylinder. I didn't have time to take it apart, due to other projects going on, but I'll bet that little contact switch is either corroded or broken.

 

[roy c]

Thank you so much for your efforts roy