need help,Ac 1-34 wont work,except 5.

[uglyrain]

HI
everyone,
I have a 97 grand prix gtp, i don;t have AC level 1 2 3 4,only 5 works,
i have done my research on google, replace a new resistor from autozone cost me about 25$ and it sstill wont work ,any idea how to fix this ?


thanks. alot

[UKtech]

Your correct in thinking the blower resistor is the most common cause for the syptoms you describe....i'd recheck everything you've done up until this point.if its not the resistor then the next thing to check is the heater/AC control outputs.... Battery voltage is supplied to the motor by the heater control via the resistor...at low and medium speeds the voltage is stepped down by the resistors.When using high speed the blower relay is energized removing the blower resistor from the circuit (hence your paticular problem usually being the resistor failure) Battery voltage is then applied through the relay allowing the motor to run at full speed.

Good Luck

[Fortune50]

Could be a failing ignition switch, check these fused circuits for power (12v) with the keyswitch turned to ON (or RUN) with the fan switch turned on to one of the lower settings:
HVAC/CTRL 20 amp fuse.
DIC/HVAC 10 amp fuse.
If it shows no power or less than 12v (especially if the same problem at both fuses), then the ignition switch is probably failing (kind've common issue).
If it shows 12v at both fuses, then you'll need to check for power at the blower motor's plug in. If there's power there on the low fan speed settings, but the blower motor doesn't seem to be working, then could be a failing blower motor. If no power at the blower motor harness with the fan settings on low, then you'll need to check some wiring at the blower motor resistor's harness. Check for power at these colored wires when switching the fan thru the lower speeds: yellow wire (speed #1), tan wire (speed #2), light blue wire (speed #3), & purple wire (speed #4). If there is no power at these wires with the fan setting on the lower settings, then there may be a problem with the heater-A/C controller.
Also, make sure the black wire at the resistor harness tested to ground has good continuity.
Let us know what you try, what you find out, and if you get it fixed.

[tblake]

uglyrain, do you have the manual hvac system or the automatic climate controll system in your GTP?

[UKtech]

I presumed it was the manual......i'm pretty sure the automatic unit uses a blower motor module instead of a regular resistor no ?

[Fortune50]

Originally Posted by tblake

uglyrain, do you have the manual hvac system or the automatic climate controll system in your GTP?

X2, I assumed he has the manual system, too as there is no 1 ,2 3, 4, & 5 position fan speed switch on the auto climate system as that system actually has 7 fan positions that can be set manually via "↑" or "↓" toggle buttons. Nor would he be able to replace the auto climate's blower control module for a mere $25 at Autozone .

[uglyrain]

thanks all for helping me
i got it fixed by replace the ignition switch,i bought the ignition switch without console $61 from autozone,install,and everything works.

[Fortune50]

Originally Posted by uglyrain

thanks all for helping me
i got it fixed by replace the ignition switch,i bought the ignition switch without console $61 from autozone,install,and everything works.

Glad you got it fixed and that I suggested you check it.