setting 5 doesn't work

[jka]

I have a 1997 pontiac grand prix that the heater does not work on setting #5. I replaced the ignition switch last year because settings 1-4 did not work but now it is just 5 that does not function. Any suggestions? Thanks

[BNaylor]

Originally Posted by jka

I have a 1997 pontiac grand prix that the heater does not work on setting #5. I replaced the ignition switch last year because settings 1-4 did not work but now it is just 5 that does not function. Any suggestions? Thanks

If fan setting 5 doesn't work you either have a problem with the HVAC head unit fan position switch or the blower motor hi speed relay is not energizing. Since it works on positions 1 - 4 the blower motor resistor or control module is OK. Check to see if the blower motor relay is getting the 12vdc or ground. Fan switch must be in 5 only to check this circuit.









Thrasher CAI, DHP v1.0 PCM, SLP Headers,
3.25 SC pulley, CAIT GMAF, 2.5 DP/Hi-Flow CAT,
u-bend delete, 160 TS, ZZP Stage 1 72mm TB,
TB spacer, MSD 8.5mm wires, Autolite 103,
Goodyear Gatorback Serp. & SC Belt,
Nitto NT555R Drag Radials
1/4 ET: 13.210 sec. @ 104.490 mph
0 - 60 ft: 1.945 sec.

[phishtruck9]

Originally Posted by jka

I have a 1997 pontiac grand prix that the heater does not work on setting #5. I replaced the ignition switch last year because settings 1-4 did not work but now it is just 5 that does not function. Any suggestions? Thanks

I recently had a slightly different problem with my 2000 GT. Setting #5 would work, but would not shut off. I eventually had to pull the fuse to get it to stop. Later, my HVAC resistor blew and needed to be replaced. Works fine now.

[BNaylor]

Originally Posted by phishtruck9

I recently had a slightly different problem with my 2000 GT. Setting #5 would work, but would not shut off. I eventually had to pull the fuse to get it to stop. Later, my HVAC resistor blew and needed to be replaced. Works fine now.

Interesting point on the fuse. He could have a blown HVAC HI fuse causing the hi-speed blower relay not to energize. It's a 30 amp fuse located in the instrument panel fuse box. I'd check the fuse to make sure it's good first.










Thrasher CAI, DHP v1.0 PCM, SLP Headers,
3.25 SC pulley, CAIT GMAF, 2.5 DP/Hi-Flow CAT,
u-bend delete, 160 TS, ZZP Stage 1 72mm TB,
TB spacer, MSD 8.5mm wires, Autolite 103,
Goodyear Gatorback Serp. & SC Belt,
Nitto NT555R Drag Radials
1/4 ET: 13.210 sec. @ 104.490 mph
0 - 60 ft: 1.945 sec.