Our Community is 940,000 Strong. Join Us.


1994 Suburban, rear A/C not working


tammyiam
07-12-2005, 05:11 PM
Hi all,

I am new to this site, and I hope someone here can help me. My 94 Suburban had great rear air until a couple days ago. What seemed to happen involved both the front and rear. The air would come on in the front but when I pushed the max (recirc) switch you could hear it blowing hard, but there was barely any air coming out the vents. There was no air at all coming out the rear, using the front switches or switching it to rear control didn't help. We checked all of the fuses in the box, and took the dash partially apart. The front is now working even on max, but still nothing in the back. I went to the rear and listened for the auxiliary blower to kick on and nothing happens. There is also usually a puddle under this and the front areas when the air is on, and the only puddle now is in the front. So something is up with the rear. Is there a seperate fuse for this blower that I don't know about? I have removed the cover and spun the blower it seems to spin freely. Any help would be appreciated, it is really hot in Ohio right now.

Tam

suburban_lee
07-13-2005, 01:00 PM
The problems front and rear sound unrelated - maybe you just noticed them at the same time. I'd start by dissasembling the passenger's side panel in the rear to get to the rear blower. With the rear blower controls set to on (the one up by the windshield), check for power at the blower. If you have power, I would suspect the rear blower motor. If not, I would start with the frontmost rear controls. Your drivers control is going to be the master, overriding the rear controls, so if there is a control problem, it is likely to be there.

As for the lack of condensation in the rear, maybe the lack of airflow across the rear evaporator explains that - It also hasn't been very humid in these parts for the last week or so (OH - KY).

tammyiam
07-24-2005, 08:16 PM
We checked the juice going to the rear air, it was getting good juice 13.79 with engine running, 12.47 with key on only. We then removed the blower thinking it was probably bad. We hooked it up to a battery and it worked??? So we reinstalled it, thinking it possibly just had a bad connection. Nothing. We then disassembled the controls, and checked the juice going to them. Seemed fine there too. Does anyone have anymore ideas? We are stumped.

Tam

suburban_lee
07-25-2005, 09:51 AM
Ever feel like the rest of the world gets the easy problems?

I'm reaching here, and forgive my ignorance of the design of the rear blower, I've never had mine apart. You checked power at the blower and that was fine. You checked the blower motor independant of the wiring, and that was fine. I have a question: Does the harness contain the negative also, or did you test power against a metal surface? What I'm getting at is that if this is the case, could it be that the blower motor is not grounding out when it is installed? If the motor works by grounding, maybe try a jumper wire between a known good ground and the motor housing. The only other thing I can think of is if the blower is binding when installed - i.e., something physically not allowing it to turn, emulating an electrical problem.

tammyiam
07-25-2005, 11:49 AM
We tried plugging the blower motor into the harness without installing it. It didn't work that way either. When we tested it hooked to a battery we hooked it up to our motor home. I layed it on the steps which are carpeted over wood, and ran a wire to each side of the harness from the positive and negative battery terminals. It ran fine hooked up that way. Someone has suggested the resistor near the back blower. Someone else said that the resistor only controls the speed not the power. I am so confused.
Tam

tammyiam
09-14-2005, 09:56 PM
Well everyone, it has now been nearly tow months with no air. Not to worried about that I can roll down the windows. What I am worried about is winter is coming and it gets cold here in Ohio. So, I went to the dealer and bought a new resistor. That is what they said was probably wrong. Guess what, wrong again. The old one did look a little smoked. You know how the metal gets that purple and green tinge to it, that's what the wires looked like. My husband still thinks it is the front switch, actually he blames it on the back one. Says the kids burnt it up, but since we know that the front one overrides the back, I must burnt it up...lol. Anyway does anyone have any clue how I might test this theory. We have already hooked a voltage meter up to the rear and turned the switch on. We get power when it is on and I believe he said none when it is off. Doesn't that mean the switch is working? Allo I can say is.....help!!!!!!!

Tam

Add your comment to this topic!