Blower resistor location

[BIG-L]

Originally Posted by net_kitten

Hey Big-L, I was at the dealership today for the same problem you described. Sometimes if I turn it below 5, all the lights go out, dash, headlights, defrost goes screwey. Of course they found nothing wrong with the car and said bring it in when its doing it ...like thats going to happen.

Of course they had to repeatedly tell me how in 20 years they have never heard of this happening and how HE owns a 99 and never had this problem. well gee, I guess if youve never heard of it and your car doesnt do it, then Im just making it all up *rolling eyes*

thanks for the post, Ill pass it on to my husband!

Im glad that some of my post are helping other's in the GrandPrix community.

Ive found that if you turn off the fan before starting the car,there wount be such a voltage spike in the Ignition Harness/Contacts and some might be able to keep the harness lasting a bit longer.

~Larry~

[mrbertnoternie]

Hey there everyone that is having the problems with the blower resistor this link might just help you fix it yourself.
http://gim.li:9001/servlets/BlobShtm...del=Grand+Prix

[MR ZAMBONI]

Is there any way to test if the ignition harness that you write about is really bad? I have a 98 Grand Prix and it sounds like the same symptoms, but I'd like to test before trying to replace, if possible.

[Adam_London519]

Good day, our car vibrates like hell when we turn the heat past 3.... and then low and behold today when its minus 27 celsius the only setting on our instrument panel that works is #5. Through research I see the problem is most time associated with Blower Resistor part #ru60. But what about this wicked vibration? Woould it be best to replace the entire blower motor instead of just doing the resistor??

To all those who post thanx very much, I hope to save some $$$ doing job myself in the balmy Canadian air! LOL

[Phoenix69]

The above link doesn't work, can you repost one that does?

[jay69dogg]

I started experiencing the no fan at settings 1-4 and only working on 5 issue on my 99 Grand Prix GT. If I turned to a bad fan setting, the motor would stop blowing. When I went back to 5, I would have to mess with my temp control knob to get it to come back on. I also noticed that my headlights would turn off on the bad settings. According to Larry's post, this meant that the ignition harness had gone bad. And he was right. I tried a new resistor pack first but that didn’t fix it. I did install a new resistor pack anyways because the green coating on the factory resistor PCB had gotten very hot and had begun to peel off. I figured no point in ruining the new harness if the resistor pack decides to go. And there's the potential fire hazard if something were to contact the hot, exposed resistors.

Here's how I troubleshot:
I pulled the connector off of the resistor pack and tried measuring voltages at different fan settings. I placed my negative lead on Pin E. It has a black wire so I'm guessing its ground. I had 12V on pin G. I cycled through each fan setting and measured every pin at each setting. I was getting 0V on all pins except Pin G, which had 12V on all settings. This told me that the harness was probably bad. I went and purchased the harness, resistor pack and nutdrivers. I connected the new resistor pack to the motor without mounting it. The motor would only work on 5 so I went for the ignition harness.

Ignition Harness Removal from the steering column:
Disconnect the negative terminal from the battery.
Remove the lower panel on the driver side that has the 2 plastic push locks and a light.
Remove the 2 screws that secure that lower steering column cover. Pull the panel towards you and the clips at the top should release.
Remove the tilt lever by pulling it out towards the door. (There might be more to it but that’s all it took on mine.)
With a #20 Torx, remove the 2 screws that hold the steering column lower shroud. The shrouds have two tabs in the back that interlock them together. Pull the front of the shrouds apart and then maneuver the lower shroud back to get it to unlock from the upper.
Using the 5/32" Micro-tech nut driver, remove the 2 male Torx screws that hold the upper shroud.
Get the upper shroud's lip out of the steering wheel and gently tilt the upper shroud back towards the gauges.
Locate the small hole in the metal cylinder where the key cylinder is. Note: These parts are located under the shroud.
Make sure the battery is disconnected. Insert the key. Turn and hold the key to START. Then insert a 1/16" Allen Wrench into the small hole on the metal cylinder. There should be slight click sound. Remove the allen wrench and turn the key back to RUN. This releases the key cylinder. You should be able to pull it out very easily, jiggling it slightly.
Remove the upper shroud.
Locate the connector on top of the metal cylinder. Insert your finger in the key cylinder and depress the white switch. Turn the connector clockwise and it should pop out.
Remove the connector on the while plastic cylinder.
Using the 1/8" Micro-Tech nutdriver, remove the 2 male Torx screws that hold the switch portion of the harness.
Work the harness back through the opening. You may need to cut some tie-wraps along the way. Keep track of the harness routing.
Loosen the center bolt on the other end of the harness, which is located under the dash.
Pull the harness out. You will need to remove two other harnesses from this one. Note where the harnesses go. They are keyed so they should only go in one way.

Installation: Reverse the process. You may need to reinsert the key and cylinder and turn it back to OFF to get the new harnesses switch hole to align to the plastic pin in the steering column.

After I installed the harness, I tested the voltages on the resistor pack cable again and here are the voltages:
Voltages at Fan Settings
Pin Fan Setting
Off 1 2 3 4 5
A 0 0 12 0 0 0
B 0 12 0 0 0 0
C 0 0 0 0 12 0
D 0 0 0 12 0 0
E Ground
F 0 0 0 0 0 12
G 12 12 12 12 12 12

The part numbers for these 2 parts are:
Ignition Switch Harness AC Delco D1491D GM# 26068757
a.k.a. Ignition Starter Switch
a.k.a. Switch Commutateur Interruptor
Price: $64 online - $116 GM dealer

Blower Motor Resistor AC Delco# 1580571 GM#89018643
Price: $25 online - $38.50 GM dealer
Note: The AC Delco unit looks better built that the flimsy factory resistor pack PCB.

Tools Needed:
Craftsman 1/8" Micro-Tech nutdriver Sears# 41865
Craftsman 5/32" Micro-Tech nutdriver Sears# 41866
#20 Torx male screwdriver.
Phillips #2 screwdriver
Wire cutter to cut tie-wraps
1/16" Allen Wrench
5.5mm Socket, universal joint and some extensions for your ratchet size if you are going to remove the resistor pack.
A multimeter.

Sorry this is so long and a repeat, but I figured I would add some details that I wish I had known while I was working on mine. Of course, if something doesn't work for you in this post, read the rest to see if you can find the answer.

Thanks to Larry and everyone else for the info. It made this problem easy to diagnose and repair. I was glad to see I'm not the only one with this problem. But it also points out a defect in part that shouldn't go bad. All of this because you leave your fan on when turning your car on and off.

Jeremy

[gpgt98]

hey there big L and every1 else with the heater problem. I guess I have much the same symtoms. That is the switch won't work on 1-4 but does on 5 and if 1-4 IS selected the headlights go out if the DRLs are on. I guess what I am wondering would it be best to change the ignition switch and not the resistor, or to maybe do both? Any sujestions from people more experienced in this problem would be great. ( 1998 GT )

[BNaylor]

Originally Posted by gpgt98

hey there big L and every1 else with the heater problem. I guess I have much the same symtoms. That is the switch won't work on 1-4 but does on 5 and if 1-4 IS selected the headlights go out if the DRLs are on. I guess what I am wondering would it be best to change the ignition switch and not the resistor, or to maybe do both? Any sujestions from people more experienced in this problem would be great. ( 1998 GT )

This is an old post and message thread over one year old and not a good idea to bring up a post this old. It is highly recommended to post your problem in a new post for more visibility and better assistance.

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