Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum banner
1 - 6 of 6 Posts

·
Premium Member
2007 chevy trailblazer_ls
Joined
·
1,422 Posts
Discussion Starter · #1 ·
I know this isnt a Trailvoy question, but you guys sure know about everything so I am going to give it a shot. On my fiancees 2000 Grand Prix the blower stopped working. It sometimes goes on or off with the headlights(If I have the fan on and turn the headlights on it goes on, light off turns the fan off). It doesnt do it all the time and about a year ago we had the resistor changed out because it woould only work on high speed and it was fine up until a month ago. Any ideas????? cause now playing around with the headlights doesnt do anything. Thanks again guys.
 

·
Registered
2007 chevy trailblazer_lt
Joined
·
678 Posts
Going to go out on a limb here and say, thats not good. :D Never come across that before. I guess its a point of using a test light and start checking for power and ground at the connector at the blower motor. If there is a good ground and no power, then try turning the headlights on to see if you get power there. If you have power and ground, try giving the motor a tap with a hammer, either way, you will probably need a blower motor. If there is power and a poor ground, that maybe some how gets a better ground with the headlight circuit, then run a better ground wire. :undecided
 

·
Banned
2004 gmc
Joined
·
26,181 Posts
Boy, those two circuits shouldn't have a thing to do with each other unless there's some worn wires behind the dash that are shorted intermittently together. It's just not rational. I see no way that running the headlights could "improve" a ground in the passenger compartment. Are you sure there's no other forums where somebody has a schematic?

Anyway, you need a meter, not a test light, and measure the voltage (compared to a good ground) on each of the wires going to the blower. Let us know the voltages (with and without the headlights on) and then we can guess better. Meters are as cheap as $4 at Harbor Freight, I've seen.
 

·
Premium Member
2007 chevy trailblazer_ls
Joined
·
1,422 Posts
Discussion Starter · #4 ·
Thanks guys, I will look for a GP forum. It is the weirdest thing with the headlights. I was a light at night so the DRLs were on and for whatever reason they cut out and I turned them on and the blower started working. If I turned the lights off the blower would stop working. :weird: Eventually when I got home everything was fine-that was a few months ago and now my fiancee is driving the car it started again. Now there is no power at all to that panel-the defrost button doesnt light up, the ac light doesnt come on-no power.
 

·
Banned
2004 gmc
Joined
·
26,181 Posts
Then it's much easier to troubleshoot. I'd guess a stuck or failed blower finally blew one or more fuses. Look for a bad fuse, but be ready for it to blow again soon after you replace it. Then disassemble the blower and look for the dead mouse inside the turbine.
 

·
Premium Member
2007 chevy trailblazer_ls
Joined
·
1,422 Posts
Discussion Starter · #6 ·
I went out to check the fuses just now when my fiancee got back and guess what, it is working again:suicide: I wonder if it isnt tied into the headlights but the dash lights???? I am going to do a search for the GP forums now.
 
1 - 6 of 6 Posts
Top