Pontiac Grand Prix Electrical/Lighting

migrnprix

I have a 2001 Grand Prix that the ac control button will not shut off. The ac light stays on no matter what I do. The ac continues to run until I shut the fan off completly. If you turn the fan back on the ac light comes back on as does the ac with it. Not much knowledge with electrical so looking for any help that might be out there. Thanks!!

derekstolpa

No matter if my car is running or of the key is just in the ACC position, I noticed that the heater fan could slow to a crawl and at the same time the DOC would go black and reset and there is a click which I assume is the relay for the auto day lamp feature. Anyone else have this have this happen? I was able to make it happen once or twice before changing the fan speed from 5 to 4, etc.

gmcustsvc

I can check my resources to see if there's anything I can help with, derekstolpa. What year and model is your vehicle?

Sarah, GM Customer Service

derekstolpa

Sarah,

Thanks for responding! I have a 2003 Pontiac Grand prix GT with a 3.8L v6. Fully Loaded.

aarjan

This sounds similar to the issue I am having with my 99 Grand Prix GTP (3.8 L).

We first noticed an electrical issue when the DIC started to go dim and reset itself off and on. It has gotten progressingly more frequent and when the DIC is lit, it displays incorrect information. Now, it is usually does not display at all.

Now we are having a similar problem with the heater display. It starts flashing or quits displaying entirely. When it is flashing, the heater fan does all sorts of weird things. It either blows really high or blows in the wrong location or doesn't work at all.

I personally think it is an electrical short somewhere. I've read in the forum that changing the ignition switch helps in some cases. This is a $300 part and I don't want to replace it and still have the same issues. My mechanic wants me to bring it in to get it diagnosed but I have had computer/electrical issues with a previous vehicle and it is extremely hard to diagnose (and very costly).

gmcustsvc

derekstolpa,

Have you already checked out the fuses and relays (there is a section in your manual starting on p. 5-95 if you're not familiar with where the fuse blocks are located; it includes a diagram of what fuse corresponds to what vehicle function)? I checked my other resources, but was unable to find any specific things to look into aside from that (I apologize - my technical resources are limited).

Sarah, GM Customer Service

aarjan

I took the advice of this forum and changed the ignition switch. So far so good. My recommendation is to replace this switch first if you are experiencing any weird electrical gremlins. Chances are that this will resolve all of the seemingly unrelated electrical issues described in this forum.

derekstolpa

I will look in the morning. To my experience either they work of they don't so when I am looking at fuses and relays, I am not sure what to look for. Today, I went to manually change the fan speeds and the DIC went black, reset, and then came back on again so it is something that affect the circuit with the heater blower, DIC (no other dash lights or anything), and during the day when this happens I clicks the relay for the auto sensing daylamp feature.

Also now today I thing I have some kind of sensor going bad in my shifter counsel. Often I cannot get my key out when I park my car. However, if I play with my shifter until I hear a little click in the dash (relay) I can then turn the key back and release it.

Not happy for a car that I baby and has only 60k on it for a 2003.

jreck87

jreck87

I have a 99 Grand Prix SE 3.1L and I have been having an issue with my lights dimming(all lights, dash lights, headlights, taillights, interior lights) and my blower motor for heat slows down when im at idle, but as soon as I give it gas or start to drive, the lights brighten back up like they should be and the blower motor blows hard again like it should. Any ideas on how to fix this? FYI, I have replaced my Alternator, Battery, and Serpentine belt so far and it still hasn't fix the issue. Also all my Fuses seem ok. This car does not have HUD or any fancy features like that, its the basic SE model but does have power windows, locks, power driver seat, etc. Any help would be appreciated, Im at a lost at this point and so tired of putting money into this car.

jreck87

I have a 99 Grand Prix SE 3.1L and I have been having an issue with my lights dimming(all lights, dash lights, headlights, taillights, interior lights) and my blower motor for heat slows down when im at idle, but as soon as I give it gas or start to drive, the lights brighten back up like they should be and the blower motor blows hard again like it should. Any ideas on how to fix this? FYI, I have replaced my Alternator, Battery, and Serpentine belt so far and it still hasn't fix the issue. Also all my Fuses seem ok. This car does not have HUD or any fancy features like that, its the basic SE model but does have power windows, locks, power driver seat, etc. Any help would be appreciated, I'm at a lost at this point and so tired of putting money into this car.

reggis2

Any suggestions on how to repair or find problem with heated seat? Turn it on and nothing happens.

reggis2

reggis2

my heated seats quit working on my 2001 grand prix gtp uprcharged 3800 engine. Is there a fuse somewhere or how do i fix this?

yourmechanic

It could be two things.

Check the relay and also check the heated seat element (it is the metal mat located inside of the seat that heats up).

2collies

Eight months to the day after my headlights went out for the first time it has happened again. Last time I changed the Headlight Relay in the engine compartment fuse box and didn't have a problem for 8 months. This morning no headlights again. Everything else works and no matter if the switch is on auto or on, the headlights don't work. The brights work and everything else too. I changed the relay again, didn't work. I took the new relay back to the store and they gave me another one, still didn't work.
Anyone have any ideas?
Thanks again,
Mike

kckinnc

if funny i have the exact same problem with my 97 and i dont know what it is i am the 2nd owner of this car i have also checked fuses and nothing i was told the previous owners child tried to install a aftermarket radio and i checked and the factory harness is still in tact .... any ideas would be great ... thanks

pam54

Did you ever figure out what it was? I'm having the same problem.

2collies

The headlight problems continue...
My 2006 GP now has 175000+ miles on it and the problem with the headlights continues. Occasionally the headlights will just go out but the car doesn't recognize that the lights are off. Everything else works fine. I have twice replaced the relay in the fuse box and now the daytime running lights were staying on. I took it to an "auto electric" specialist who could not figure out the problem but did succeed in charging me $350. I took it to the dealer who spent hours looking but again, no solution. Now the DRL are staying on after the car is off. At least the dealer didn't charge me anything. The relay was hot as hell so I again replaced it which shut off the lights after the car was off but something is frying these relays and I have no idea what. You might think 175000 miles is time to go, but the car is in absolutely perfect shape, I have done all maintenance since brand new and I am not ready to give up on it just yet. Any ideas would be appreciated as I think there must be something in the under hood fuse box causing the relay to heat up to the point of malfunctioning.
Thanks for any ideas!

seanwilkirson

My 2000 Pontiac Grand Prix GTP has has a couple of issues since I bought the car last week. I can't drive it at night anymore because I don't have tail lights, I have brake lights, just no tail lights. Along with the tail lights my entire speedometer, tachometer, radio, AC/heat, etc. is pitch black. The first night I noticed it, the lights went on and off a couple of times while driving, but not exactly when I hit a bump or turned hard, but now they stay off. Along with this, my car chime keeps binging even after I take the keys out. Another problem I'm having is 9 MPG, I know I need a downstream o2 sensor, but my car says it's running lean which means less gas right?
So basically, I would like to know if it's an electrical component that goes bad, or if there's a short somewhere (ugh) and if my o2 sensor will double/triple my mileage.
Thanks.

icechips

Lights, DIC, Heater, no action

My GP is a 2001, 127,000 miles, reading this wonderful forum I think this problem is the ign switch or a grounding problem.

Since fall my problem is: I would shut her off, turn her back on no DIC, heater fan, dash lights, headlights, heated seats... Can turn headlights on manual & get dash lights. Radio is fine, think the overheads work. Sometimes would be driving & all this would go out.

Sometimes in the beginning I could shut her off & on & it all came back.

Lately I've noticed. If it's not working when I turn her on, about 5 minutes down the road all comes on & stays on until I shut her off. Or it comes on for 5-10 seconds, shut off again & about 5-10 minutes comes on...usually stays on until she's shut off.

Last night it did three cycles of on off on for 10-15 minutes, off for a minute then stayed on.

No lights come after I manually put on head & dash lights. The only odd thing is this whole time I'll get a low coolant light, but once the temp gauge moves off of 160, my lowest temp, the light goes off...& this is about this about the time all the electrical things come back.

One other thing...I had the ignition switch replace maybe in 2013, summer, the key was stuck in the ignition.

And if you ever have the traction control drop off, it's wheel sensors whether they show bad or not..

Hopefully someone can tell me if they think it's a ground popping off & on or I need another ignition switch (& is it still effect if you fix it once you shouldn't have to pay again for same part at dealer?

Thanx!

pontiacmiblues

kpg102 said:

I have a 99 Grand Prix GT, 70K miles, and have had shifting/key problems with this car for a few months.

My current problem is that occasionally the car will not shift into Park. Sometimes if I just keep shifting all the way down and back up, it will eventually go into Park, although usually with some resistance. Last night I had to drive it around the block, and then I was able to get it into Park but with more than a little resistance.

A couple of months ago, I experienced the "stuck key" problem: the ignition would not turn all the way to the "off" position, and the key would be stuck in the ignition. Left key in overnight and it ran down the battery. Took it in for repair in December, and they said the solenoid on the shifter was defective and they had to replace the whole shifter (cost me about $400).

Anyone else experienced similar problems, or have any suggestions on what could be causing the shifting problem?

Don't know what causes it, but I have the same problem with my 2003 GP GT. Try jambing shifter into park and listen for a "clicking" noise under the dashboard near or below the steering column. If you hear the noise, you can turn off the ignition & remove the key. If you don't hear it, the key will not come out and you'll have to repeat the process until it does. Sounds goodbye I know, but it works for me.

pontiacmiblues

That was supposed to say: Sounds goofy I know, but it works for me.

jweston1979

I have a 2002 grand prix the headlights went out an have not came back on all the fuses are fine an so are the relays the blower only works on the 5 setting all the other lights work fine I can't find any ground wires off maybe its the  ignition switch that's to only thing I haven't tryed

PF_Flyer

The blower only working on the highest setting is almost certainly the blower motor resistor and not related to the headlight issue. Electrical gremlins always seem tricky to track down. Have you checked for voltage at the headlights? Found wiring diagrams online

imidazol97

@PFFlyer
You're quick. I came to post those downloaded (from bbbind.com page) and to comment that it's going to take some troubleshooting with a voltage meter to find where the power is dropping out.

Like the poster said, I'd start with checking power at the relay. There is a fuse under the hood and a circuit breaker in the Instrument Panel fuse box to check for continuity and for power.

Not for the weak hearted. But check for power at the obvious places first: Law of Parsimony. Simplest often is the place.

As to the blowers, most GM's have a power feed for the lower power draw throught the resistor pack. If the last wire (or circuit) int he resistor pack blows out, none of those lower speeds work. There is usually a fuse on that line. Then there's a second higher fused circuit that gets power to the highest speed through less wiring because it's a higher draw. Check both fuses and the resistor pack.

OP can get a circuit diagram for the blower at bbbind.com. Just register and use DIY as your company. It's a great resource. Members at autozone.com can get similar diagrams.

imidazol97