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Pontiac Grand Prix Heater blower relay switch



  • ihgirlihgirl Posts: 1
    My 2002 Grand Prix GTP has lots of problems....the ignition switch is most likely the problem. I'm trying to find where I can order the part, I'm in Canada and can't find "Ignition Switch" anywhere. I have found it on the USA sites. Any help would be great.
  • russdartsrussdarts Posts: 1
    I have 1998 Grand Prix GT the heater blows only hot even when set to cold. My rear defog and air conditioner buttons don't light up . any ideas
  • Hi,
    I have a 2006 Pontiac Grand Prix and have had the same problem occur in 2008 and again just a few days ago. Both times it was the A/C Power module that had to be replaced. When I replaced it in 2008, there was a service bulletin about the problem, but no bulletin this time according to the dealer. There is an obvious problem with this part, as I just picked my car up today and after driving for 30 minutes, the problem re-occurred. At least this time it will be a warrantee repair, but that doesn't make up for the inconvenience. Good luck!
  • busmechanicbusmechanic Posts: 1
    edited October 2010
    Replacing the blower motor resistor/relay assembly on the 2001 Grand Prix only solved getting the motor to run on #5. The main electrical wire to the ignition switch sounds like the culprit. I got my diagrams from to help diagnose the switch. All voltage from #1 thru #5 from the switch was slightly less than 12 volts but still managed to pull the relay in for the high-speed fan. All other positions from 1 thru 4 turn off the auto headlights and no blower motor action. If you ask me GM should have a safety recall on all vehicles with this type of set-up. There is no reason to loose headlights while driving and trying to keep warm or cool.
  • You need to replace the ignition switch! As crazy as it sounds that is your problem! You see all the voltage rubs through the ignition switch. If the there is a disruption of voltage running through the circuit the ECM won't allow the blower to operate at 100%. It's fairly easy to do, but make sure you don't damage the Pass Key III, to take it off you will need to use an ice pick or something like that to remove it. I replaced my ignition switch and it solved all my blower problems!
  • Thank you. No, it is not so crazy. I did quite a bit of research on many forums and came to that same conclusion. Unfortunately for me, I took the car to a mechanic and I can't seem to find the original key with the computer chip in it. So, it is going to cost me an extra $150 for that. I suggested to him that replacing the ignition switch and getting a new key should all be a one step process.
    I can't believe that Pontiac hasn't called in a fix on this. I can't tell you how many people I have seen with the same problem: that stupid leaky area between the hood and firewall, water gets in and, well, you know what they say about water and electrical stuff - they just don't mix. :sick:
  • my blower is working fine but now heat. The car was acting like the thermostat was going out this morning. when I started the car it wen directly to half way on the therm. blower was working no heat. Once the car got to danger area the heat started to work. changed the thermostat after work and the heater doesn't blow hot.Any ideas?
  • Check your coolant level, and also I had the same problem and it was a cracked radiator cap! cheap fix!
  • i changed the ign. switch delco about 100.00 and two hours not that bad.
  • if you are using dexcool and have not changed it it could be a clogged heater core had that problem with 98 Tahoe.
  • so a good sys flush could help? no heat, and now in the upper 20's, damn cold ride to work and back.
  • klmoonklmoon Posts: 1
    Purchased 07 Grand Prix a few months ago in the summer. Not that I am using the heat, I am having problems. Blower works fine, but no heat, barley warm enough to defrost windshield. Sometimes if you let it run awhile, drive a bit, then stop for about 20 mins, sometimes we have heat. The more times you stop for a bit, the more heat you have. Have changed thermo w/ GM part, also had system flushed and filled. Still no help...any ideas? Thinking heater core, but passenger side does not get wet. Please help someone it is -5 her in KC today, heat would be great.
  • My heat stopped working consistently about a month ago in my 2002 Grand Prix SE, at first I was able to kick around underneath the dash and it would come back on, so I just assumed something was loosely connected, but it has eventually since died out and nothing will come on at all. No air is blowing out of any of the vents whatsoever, hot or cold. I have no other issues with my car, just this situation with the heat and in the middle of winter dealing with below 0 temps most of the time, it makes not only for a cold drive, but near impossible to see with how frozen my windows get. I bought a little dash defroster/heater that plugs into my 12v as a temp fix, and have an appointment scheduled with the mechanic in a few days as I cannot handle this anymore with the cold temps outside. Any idea what could be the main culprit? :cry:
  • I have two possible solutions for you. First, a $10 part - check the blower motor resistor. It is located behind the AC motor, kind of hard to get at but with small hands its not too bad. You can google images and schematics. Second, and seems to be a consistent problem with the Grand Prix, the ignition switch. Sounds odd, but apparently all the wiring runs through this switch (where you put the key in). Be aware that if this is the problem, the next issue you will have is that the car will intermittently not start at random times. Good luck. ;)
  • burnszburnsz Posts: 2
    Fan does not work in settings 1 and 2, but 3 - 5 work just fine. Does not matter if for AC or heat. Is this the switch or some other relay? Is it an easy fix?
  • The simple fix for my situation, which is very similar sounding to your problem was the ignition switch. Once I changed it out the rear defroster, daytime running lights, fan and A/C all worked as if they were new. GM mechanics wanted to change out the relays and resisters @ $150 a pop plus labour, I'm glad I found the solution on this forum. Good Luck!
  • burnszburnsz Posts: 2
    I have read the previous message regarding this issue and it seems often that the ignition switch was the problem for many of the electrical issue on the dashboard. I presume this is the switch on the steering column and that it is relativley easy to replace yourself. Are there any special tools required (I read an ice pick was handy)? I am not having any of the other electrical problems, just the fan in positions 1 and 2, 3-5 work fine.
  • The one thing I would caution on replacing the ignition is to remember that the key (depending on year) has a computer chip. If you have to replace the key it will cost a lot more. Unless you can figure out a way to bypass Pontiac.
  • That happened to my 2003 Pontiac Grand Prix, eventually the 4 stopped and yesterday nothing at all.

    I had the dash torn apart and was told that Pontiac did not put the cabin filter in so there was dirt and paper in the fan. He cleaned it out but never got around to getting me the part I needed to repair it.

    Good luck
  • ejones86ejones86 Posts: 4
    What I want to know does this ignition switch problem also go for the newer grand prix's I have a 04 and my heat/defroster/air also only works sometimes. Then when I need it too work it makes a clicking sound like it wants to come on but never does anything. So I should I have my ignition switch replaced as well
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