Heater A/C control trouble??

[brawley]

my heat and AC work fine, the blower switch only works on high though it will not work on the lower settings? is the switch-control panel itself bad or could it be a relay or something else. there is also a chirping sound coming out of the heater box ?? do I need a new blower resistor or motor?? thanks for any info.

[brawley]

this is in a 1995 chevy truck. thanks

[stevejohnson48]

Originally Posted by brawley

my heat and AC work fine, the blower switch only works on high though it will not work on the lower settings? is the switch-control panel itself bad or could it be a relay or something else. there is also a chirping sound coming out of the heater box ?? do I need a new blower resistor or motor?? thanks for any info.

Its probably your blower resistor if it only working on high ??/ But check your resisters first ??/ all three are the same on my 90 so bought one somewhere around $11.00??/ change out one at a time always using the new one to check the circuits with every thing on ??/

[sntrym95]

If the high setting works but the others don't, then it's likely the resistor. The high setting powers the motor through a relay, but the other speeds go through the resistor.

See my thread on troubleshooting heater/AC issues and links to service manuals with schematics here: http://67-72chevytrucks.com/vboard/s...d.php?t=582888. Scroll down to the bottom for the service manual link.

[400sbctruck]

what they said!