10 Amp Hvac Fuse Keeps Blowing?

[07SilveradoClassic]

07 crew cab LS1 I noticed that when I adjust the temp adjust slider for some heat nothing happened, then I tried switching between vent to defroster and nothing, knowing this is not the old vaccum system, I checked the fuses and found the 10 amp HVAC fuse blown, I put the spare one in and it all worked again... for a little while then blew again?? the AC and fan works fine? Anyone have any ideas or had this problem?

[07SilveradoClassic]

I guess this must not be a common problem, bummer

[txab]

Well you have an overdraw problem, you know that. Could be a wiring problem or could be one the actuator motors having problems and causing the overdraw. That's my .02.

 

See if anyone else has any ideas....

[zibzer]

Well you have an overdraw problem, you know that. Could be a wiring problem or could be one the actuator motors having problems and causing the overdraw. That's my .02.

 

See if anyone else has any ideas....

 

Never heard of overdraw. overcurrent is the real term. Anyways, either you have an intermittent short or a motor is dying on you. you'll have to trace the wiring (a schematic may come in handy) or figure out which motors are on the circuit. You can disconnect the motors and test them on a bench with an ammeter and proper 12v power supply that an electronics guy would have. (or you could use a 12v car battery and test leads... An ammeter would still be recommended). A little electronics knowledge is required. If you don't care to do all that simply replace the motor and hope it's not a dead short due to a frayed wire. Ifyou still have the problem. You'll need to find the short. Good luck. Btw I'm an electronics controls tech

[98 Z71 SLT]

Your blower motor resistor is fried. Common problem. Remove blower nmotor resistor, and check your wiring at the resistor. You are going to see a melted wire, at the resistor connector. Get a new resistor and fix up the wire, and you'll be all set.

[07SilveradoClassic]

The blower works fine as all speeds as well as the AC button and recirculate button, The fuse that blows seems to control the temperature adjustment sliders and the vent, floor, defroster selection knob.

 

I was hoping others may have experienced this. I know the actuators are not vacuum anymore. I am going to grab some fuses and try to see which knob or slider movement pops the fuse, I hope it does not pop right after I install it. When I replaced it the first time this weekend I tried all the vent positions and moved the temperature sliders and it all worked, I only noticed a few minutes later that it had blown again. Thus I posted on here hoping for some advice before I went any further, not that I really know where to start.

[07SilveradoClassic]

Its not the controller, I unplugged it completely and it still blows the fuse, I need a HVAC Schematic!

[07SilveradoClassic]

Help!

[07SilveradoClassic]

Just gets funnier, went to go find a manual at the parts house and they stop at 06, I assume it must be an actuator, would like to know the wiring to check before I start digging in

[07SilveradoClassic]

Ok unhooked all the actuators and hooked them up one at a time, it looks like the damper motor that controls the outlets is the one causing the blown fuse, The Haynes manual has nothing on it, is it a dealer part only?

[98 Z71 SLT]

Air mix door actuator sounds more like it

 

Junkyard dude...probably like $10

[07SilveradoClassic]

I dont know what its called, but its the actuator near the gas pedal that controls where the air comes out. I did not think about the salvage yard! Thanks