Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!

Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!

Have you recently switched from a luxury sedan to a luxury SUV?
A reporter would like to talk to you; please reach out to [email protected] by 7/25 for more details.
Did you get a great deal? Let us know in the Values & Prices Paid section!
Meet your fellow owners in our Owners Clubs

Pontiac Grand Prix Heater blower relay switch



  • Hi,
    i replaced now the ignition switch and it works all perfect
    again. Thank you to all who help me. The devil magic electric
    problems are away.

  • HI!

    But, did you have any trouble with the transponder key security system, in that when u disconnect the ignition switch, the system wouldn't start the car, & u had to pay a dealer to re-set it?

    That's my concern/so many people have reported this happening.

    If anyone else has replaced the ignition swich to cure the heater/air problem, please respond, & tell me :

    1) the year/miliage of the grand prix (mine has 45,000 miles (heater hasn't worked since about 38,000 miles).

    2)The engine size u have.,
    3) Any way around the possible security key drawback i just described??

    4) Also, if the heater controls don't work, does this create a problem when flushing the cooling system(e.g., don't u need to ctivate /divert water to the heater core, in order to flush thru IT too???

    w. older cars u did.
  • I have a 97 grand prix that the blower motor went out on all speeds. When this happened it took out the horn, windows, rear defrost, keyless entry, wipers. I have taken it to the garages that "specialize" in electrical but no one has answers. I have tried/ checked all fuses, in dash and under hood. Any suggestions?
  • Check your ignition switch. It's real easy. I did it myself! The part will cost you about $100, when you take it apart be careful not to damage the pass key III. There is a small hole on top of the key cylinder. Take a ICE PICK and place in the hole and then put the key in the ignition. The whole cylinder slides right out and then disconnect. It's real simple if you have a diagram. I found one by going to google and searching "ignition switch removal for a 1997-2003 Grand Prix. I got step by step directions (with the exception of the pas key removal...which I mentioned earlier) and it was done......Also make sure you have an inverted torx set ($20). You will also need to go to Auto Zone and get the small inverted torx bit ($5)...I believe it's a a #4! To take everything apart and put back it should take about an hour....and no reprograming necessary. Unplug then plug back in. The reason it's your ignition switch is that all the voltage goes through the ignition, and if there isn't enough juice to operate the computer will take it away in order for the ignition to work.
  • My blower works awesome,I just can't get it to stop blowing off my feet.speed is fine direction is not.Any suggestions?
  • hello all,

    I have a 2005 pontiac grand prix and on my climate controls when i got to turn the
    blower fan knob to adjust it for a certain speed it only stays at one speed and also it will not turn off even when the car is off and knob is in the off position.It keeps running constantly.What do I need to check and where.Thank You
  • I replaced the ignition switch still no power to all the above mentioned components, when i was replacing the switch i noticed a bunch of wires spliced in to it under the dash. any idea what these are? im about ready to just junk the car, should know better than to buy a gm vehicle, they have raped the american car buyer for years and now they are raping the government for money to bail them out because their engineers cant build something that lasts without major hassels
  • buddy49buddy49 Posts: 1
    Where is this box located
  • My grand prix was doing the same thing 1-4 fan motor does not work and sometimes #5 speed did not work. The problem could be the Ignition switch, Lock cylinder or both. I just went thru all that crap, heres what to do. Its easier to replace the steering colunm. You will have 2 keys then but can be fixed in about 1 hour. Go to a auto salvage and get a used one the cost is about $125.00 or there abouts. This will fix most problems cause the ignition controls everything.
  • sweetratssweetrats Posts: 7
    After much research, I can tell you that the problem is caused by water leaking in to the car though the hood gasket. The water leaks into the interior onto the blower motor relay and sometimes travels along the wiring causing shorting and corrosion. Unfortunately, just replacing the relay won't permanently fix the problem. Caulking the gasket helps until the caulk becomes unstable and the leaking starts all over again.
    Unfortunately, the relay is located in a difficult place to access - on the firewall behind the AC motor.
    Some of you may have noticed that the carpet on the passenger side of the car gets wet when it rains. . . . . . ....... :P
  • 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
Sign In or Register to comment.