Hi. I've got a '99 Blazer that I just bought a few weeks ago that has a couple of minor but irritating electrical problems.

1. The dome light doesn't come on when any of the doors are opened but does come on when the dimmer wheel is rotated to one end or the dome override button is pressed (when the doors are open). The really strange part about this is that when the light is turned on this way the alarm systems arms.

2. The latch for the hatch only operates when the interior opener button is pressed, not when the button on the back of the truck is pressed (as it used to do when I first bought it).

Any ideas?

 

Sounds like whoever installed the alarm hooked into a wrong part of the wiring, therefore messing up other circuts. I would trace the alarm wiring to were it wires to, disconnect the wiring if possible and then see if after that the dome light works and if the hatch button works. I may be wrong but its a possiblity.

 

on the first issue, trace the white wire from under dash at the courtesy light. My guess is they put a diode in facing the wrong way.

 

Thanks. I'll have a look for the diode next chance I get and let you know what I find.

 

I found out what was causing the "dome light/car alarm" problem. As usual, it was a short circuit between my ears rather than any physical problem.

The car alarm has a passive/active mode which can be changed using the remote. In passive mode it arms itself when the last door is closed (ie. the dome light goes off). In active mode, it's not armed until you manually do it via the remote. I switched to active mode and now I can have the dome light on when I open a door. What a luxury!

Still can't open the tailgate (except from the dash button) tho.