I have a 1999 Chevy Suburban. The blower fan for the heater/AC was only working on high so I replaced the resistor and relay at the same time. Still no change so I replaced the switch and 30 amp fuse. The first three settings worked but not the high. I checked continuity of the wires between the switch and relay and they were fine. I then thought it might be the blower fan which I replaced but still not working on high. I am stumped. Any suggestions?
@Swim7 closely look at all the pigtails (blower and resistor). GM has known problems with melted pigtails.
The contact on the switch which carries the current from the fuse block looks burnt. This sits next to the wire for the high setting. Could this be responsible? I would think it would effect all the settings. I don’t think the resistor is involved because the high bypasses it and goes directly to the relay
@Swim7 Yes this is the next part that must be replaced.