2002 gtp electrical issue?

[thecrow1986]

2002 grand prix gtp 260,000 miles but babied, problem is when i start the car everything is all fine but as soon as i turn on the heater blower it kills the headlights and blower wont work till i reach five but no headlights till i shut off the blower? new blower already and no diff. also when i switch the blower speed back and forth the body controil module clicks. any ideas?

[olopezm]

That's a typical symptom of a flaky ignition switch. You can check the Tips and Maintenance section for a guide.

Oscar.

[thecrow1986]

so even with the car starting fine and no problems getting the key in and out?

[olopezm]

Yes, I would even dare to bet your tire pressure monitor is not working either.

Oscar.

[thecrow1986]

my car doesnt have tpms lol. heres a rundown of what has happened. lately ive also seen water on passanger side floor after heavy rain. last heater blower burned out. put new one in. problems were there before and after new blower. start car and drive it everything is fine, once u turn on the heater knob the drivers information center goes out and the headlights go out. blower will only come on at speed 5 and then the headlights and information center come back on.

[olopezm]

I don't have a DIC, but had the same symptom with the headlights and blower motor when the ignition switch started to fail. I didn't know about it back then and kept driving the car; it took a long time until the starter started to have some lag between the moment I turned the key and the moment it actually engaged, it got worse that sometimes it would be 2 seconds between each event. Everything else was normal and had no other problems during start.

Oscar.

[danielsatur]

Start with the cheapest Test 1st.
1) Make sure your battery terminals are clean & tight.
2) Have both the alternator + battery load tested at the local auto parts store.

There's a lot of demand for electrical power on todays autos, a marginal battery can cause a flaky
BCM problem.

There should be plenty of spare BCM's in the local bone yard.
The Blower Control module is connected to a BAT fuse, it's on a unswitched circuit.

[olopezm]

If you search the forum for ignition switch, you'll find that the lights from the DIC not working are also a symptom of a failing ignition switch.

Oscar.

[rkvons]

Originally Posted by thecrow1986

my car doesnt have tpms lol. heres a rundown of what has happened. lately ive also seen water on passanger side floor after heavy rain. last heater blower burned out. put new one in. problems were there before and after new blower. start car and drive it everything is fine, once u turn on the heater knob the drivers information center goes out and the headlights go out. blower will only come on at speed 5 and then the headlights and information center come back on.

Water on you passenger side floor indicates that a deflector has fallen down under your windshield wipers on the right side. You have to kind of remove the plastic cover at the base of your windshield and peak under it. If you can see the blower there, your deflector has fallen down and needs to be put back. Better re-glue it.

[gmtech1]

Originally Posted by olopezm

That's a typical symptom of a flaky ignition switch. You can check the Tips and Maintenance section for a guide.

Oscar.

Agreed!

[thecrow1986]

fixed the leak. now the electrical problems keep getting better, now when i turn on the heated seat a buzzing sound comes from the seat. still ignition switch?

[Tech II]

See if the heated seat module is doing the buzzing......with the water leak you had, there may be corroded grounds under the carpetting....

[thecrow1986]

i fixed the water guard flap by the windsheild, so the leak is gone i also pulled out the blower resistor and it looked awful. it was rusted solid from the water pouring on it. i changed the risistor and it works here and there but basically the same as before. where are thos grounds? and yea the buzzing comes from the heated seat resistor.i also tried grounding the battery to see if the battery had a bad ground but no change.

[Tech II]

Is the module buzzing or the seat grid, two different things(module located under the seat).......did you ever lift the carpetting on the passenger side and feel underneath? If soaked, there might be grounds underneath there that are corroded.....if soaked the carpet should be removed......you will have bacterial growth/mold that will create a smell...

Need a schematic/manual to locate the ground for the heated seat system.....

[thecrow1986]

its def the module under the seat. as far as the carpet there no smell. i have a auto steam cleaner and i removed the water right away and spayed it with antibacterial spray for mold