AC, Vents, Defrost not working

[Turbo-T Wannbe]

A couple weeks ago, my heat, AC, vents, defrost all stopped working. I know the AC is working, but nothing blows out the vents at all. If I turn the vents on and am driving, I can feel a small amount of air coming out, but not much. Nothing at any of the fan settings. Is my blower motor just not working? Is it shot, or is there some relay that could have gone bad? I don't see any fuses blown, and don't know what to do. Help me, it's too hot in FL for no AC.

 

[Steve Wood]

You should be able to hear the blower motor run...if it is not running, it may well be dead...just jump 12 v off the battery to the blower motor and see if it runs...if it does not, it;s time for a new blower motor...cheap from the parts house.

 

[gnXfan]

Mine was the fan switch.

 

[Turbo-T Wannbe]

Thanks for the tips guys, but I'm an electrical idiot. Where do I tie in the lead from the battery to the motor? Is there some type of contact on it I can use? Also where is the fan switch located???

 

[Steve Wood]

Run a wire from the positive battery post to the terminal on the blower motor that the purple wire goes to.....just touch one end of a wire to the battery and the other end to the blower motor connector that has the purple wire...you will have to probe down into the connector to make contact.

Switch is the blower switch on the dash...

It is most likely, the relay, the motor, or the switch.

It is easier if you have a volt meter or test light.

 

[wagon]

If the fan is running, then you may have what I have. I run alot of boost, and that boost broke through the check valves in my vacuum lines. Check the check valves and see if they check. I took three out of my car, and all three were blown/popped. Once the check valve for the heater pops, the next things that pop, are the air bladders for the vents. I have to tear mine out and replace them. Once you turn on the heat, you get a vacuum leak. Also, having a blown check valve ruined my cruise control. It inflated the bladder, and the internal springs popped out of place. Now the cruise is all messed up. Just something else to check.

Brian

 

[elcaminov6]

Another thing to check is the speed control resistors, which are mounted to the plate the purple wire goes to. Just pull the two screws and the plate will pop out of the heater box. A quick visual inspection will reveal some coiled wires. These provide fan speed control via different resistance levels, and if there are any broken wires, that speed will not work...

 

[1970gsx]

If the suggestions above don't help, you may have have a shorted 12v supply to the fan switch like I had. I ended up running a new 12v supply to the switch with an inline fuse.
Dead of winter when it happened also. This one took awhile to figure out because the purple wire at the fan had power when pull off and tested, but when connected and tested the volts dropped to zero.

 

[Turbo-T Wannbe]

Thanks guys, I'll check these things out this weekend.

 

[Fuzzy]

I know of one check valve which is behind the coil pack in the engine compartment. Where are the other two?

 

[Steve Wood]

egr feed, charcoal cannister feed

BUT! we have no air anywhere and no sound of the blower running.....we don't have a vacuum problem in this case. We have most likely a bad blower motor, bad relay, bad switch, or a blown fusible link.

 

[BADDGUY6]

Check valves?

Originally posted by Steve Wood
egr feed, charcoal cannister feed

Do all 3 check valves look the same? On my car the check valve by the coil is bigger than the other 2.

 

[wagon]

Yes, the one by the coil pack has two ports on one side, and one on the other. The other two are the same(as each other).

Brian

 

[Turbo-T Wannbe]

Thanks for all the help. It was the blower motor itself. $18 and now I have AC that works

 

[Steve Wood]

it's nice when it is simple and cheap...