Blower motor resistor?

Heater problem
1998 Pontiac Grand Prix 6 cyl Front Wheel Drive Automatic

Blower motor fan worked only on highest (5) speed. I changed the resistor and that fixed the problem for a few days but it again now only works on highest setting. What's my next move? Thanks!

The motor only runs on High (5) but even then it takes 20-15 seconds or more to start. It will not run on other speeds at all however earlier on, it would run on slower speeds but only after driving for quite a while.
I've tried a new motor with same strange results. The resistor module seems OK because I find around 12 volts at blower wires on High as well as the lower speeds ! The relay clicks when turning the blower switch on but when in High, the relay returns to "off" or at least to same condition as when switch is off.
I'm an electronics tech but have no diagram for the involvement of the relay side. I see two other relays and a couple of IC's on the same printed circuit board.
What may be the cause of this situation? Thanks!

Thanks very much. I already have that wiring diagram. Further troubleshooting has confirmed the motor, resistor block and high speed relay plus the fan switch are all in perfect working order.
I found that the voltage at the input to the blower switch reads low. Around only 5 volts! I tracked down the fuse (top left on on diagram) and found the voltage was low right at the
supply side of the fuse. I bridged across from the adjacent fuse (from another supply lead) to the blower motor circuit and all works perfectly!
If you pull the blower motor fuse, you may read the full battery voltage at the supply side but as soon as you install the fuse and turn the fan switch on, the voltage drops to a very low level or practically zero.
There are two small gauge pink wires supplying this fuse. I haven't tried to track them back since they are so buried in a cable bundle behind the dash. Would you know or have a diagram of where they come from?
Apparently there is a break/corrosion or high resistance buildup in the feed wire or a partial short to ground. Also wondering if this path would lead back to the ignition switch and if the problem could originate in the switch. Burned or oxidized connections.
Seems like only about a 18-22 gauge wire is used and same with the brown wire from the fuse to the motor switch. Doesn't appear to be very heavy for a rather high current draw from a motor.
Anyway if I knew where this questionable pair of pink wires goes. Physically. So as to know what to check next would help. Right now I am not sure how this pair of wires ties into the battery positive side.

I have no blower motor on the 4 lower fan speeds. High speed works fine. I have checked all fuses and checked for any relay problems. None. I replaced the blower resistor. Still no luck. I am in dsibelief that the switch would be dead on all lower speeds, yet work on high. Is this a unique problem that may be covered in a Grand Prix service bulletin? Other places to look for a problem? Thank you.

On my 1997 pontiac grand-prix se, 3800engine-series2 with 128, ooo miles on it, the blower only works on high (5) and when it is switched on 1, or 5- one click is heard, and sounds like it is comming from behind the steering wheel inside the dash. I have since replaced the blower motor resistor, but it seemed to make no difference, and also when the blower speed knob is turned to speed 1, or 5, the lights dim. What can be causing this, and can I repair it myself, and how?

Hi,

I recently (about a month ago) had my car's blower motor resistor replaced because none of the fan settings worked. About a week ago, the fans started making squealing noises when I turned them on but would eventually go away after running the fan for a few minutes. Now, settings 1-4 do not work again. Setting 5 works, but it is still making a loud squealing noise.
Also, I do not know if this makes a difference, but about the same time the fans started squealing it started to get very cold outside 20 degrees and below.

*Edit* I corrected my milage.

Are there any good instructions as to how to replace those? When I first tired to get to the blower resistor I could not get the actual blower motor out due to some wires or something blocking it. If this is something that someone with moderate mechanical skills can do let me know as I would rather not take it to a mechanic and have him charge me $100+ dollars to fix (again).

1996 Pontiac Grand Prix

my heater only works if its on full blast is that the blower resistor?