SOF Vette

I live in TEXAS (it's still hot here) and have little to no electrical knowledge, although I do own the 1991 GM service manual and the electrical annex.
That being said - I took my '91 to get the windows tinted today A/C working wonderfully.
Picked up the car - not supposed to roll the windows down for 48 hours and now there is no A/C.
The A/C unit lights up and displays the temp outside as well as my settings, but no blower.
The tint place says they didn't disconnect anything or do anything except tint the windows...not sure what to do here.
All fuses are good and the electrical connections to the blower are intact.

Any help would be appreciated.

Thanks-
SOF Vette

engle1147

Those tint guys spray a lot of liquid on the window and tint to move it around and get it in place/smooth.......check your fuse panel and make sure it didn't get wet, short or blow a fulse from excess liquid.

JimiHendrix

I took a quick look at the electrical schematics and it appears that the blower fan is controlled by relay. The relay in turn is controlled by the car's computer aka PCM. You could have a burnt blower relay or PCM problem. Not sure if that would trigger a code on the PCM or not.

Good luck!

One other way you could test quickly if you have a relay problem is to jump the power connections within the relay panel to see if the blower work. Just make certain you correctly identify the right connections to jump, otherwise, you will blow a fuse!

PBnf

Maybe if you remove the window tint? Naw, try what they said.

SOF Vette

So I went to the local dealership and paid them $40 for a diagnostic check - "Sir, your blower motor is bad. We can replace it for $208. The OEM replacement has to come from Detroit, it'll take 2 weeks."
Thanks but no thanks -
Picked up the car, drove it home. Now the aftermarket alarm doesn't work. Stealership is closed.
I head down to NAPA, get the OEM replacement blower motor for $47, put it in and hear the audible pop of the fuse in the fusebox. ARRRGGHHHH!!!!!!!

This is getting very frustrating. About ready to pull the tint off and see if the world goes back to normal...

SOF Vette

2UHONEY

S'thing doesnt add up here.
If you have a bad blower that's not popping the fuse ...why would the new blower kill the fuse?? out the back of my head from when I was a auto mechanic some 25 yrs ago all blower motors worked on 12 V, if you have the old blower out try applying 12V straight from your battery n see if it would spin at all, make sure not to invert polarity althou all that will cause the blower to spin backwards.If it spins freely n quietly at full speed then thats not your problem.
I worked for a dealership (not GM) we were wrong a lot of times. I remember once we replaced an engine on a car with 2500 miles on it because it had a horrible knocking noise and we later found out it was only a cracked flywheel, sure in this case it was all warrantee work but thats not always the case. So, dealerships are all right for the most part but dont take what they say as written on stone.

SOF Vette

Just use a couple of lengths of wire for this???

I understand about dealerships and being wrong some of the time...but I have had a rather poor run with multiple Chevy dealers in general. The LAST time I had a major issue I was told that a bushing in the transmission was bad...they tore the tranny down, all bushings and tranny were fine...turned out to be a FOULED SPARK PLUG. The OWNER of the dealership refunded my $1400 spark plug charge about 3 weeks later.

We'll see what these folks say tomorrow I guess...

SOF Vette

AdoptAVette

This my be a long shot but what the hey:

If you have auto climate control you could have a sensor problem due to the window tinting. The 91 has a solar (sun load) sensor circuit and an in-vehicle temperature sensor to help control the auto-air.

If there is a problem it will throw a code. To test for codes,push and hold the fan up and down arrow buttons at the same time for 5 seconds. The display will show -00. Push the "Auto Fan" button and the LCD will show any codes stored. Outside air temp sensor will throw either code 5 or 6. The solar load sensor code is 7 or 8.

SunCr

Electronic Air controls Blower speed by sending low voltage signals from the HVAC processor (called the Programmer) to a Blower Module mounted on the left side of the Evaporator Case (no relays are involved - nor is the PCM as running the Blower Motor has nothing to do with engine operation). That Module amplifies (roughly doubles) the voltage input and sends it to the Blower Motor. Since your Vette is blowing a fuse, there is either an internal short in that Module or the wiring is frayed somewhere. Lift the hood and find the Module. There are four wires which should be Brown (the input); Black (Ground - shared with the Blower Motor); Purple (the output), and Red Power. Examine the harness and connector closely, but since the fuse is blowing, pay attention to the power wires - red, brown and purple. If that checks out, examine the Blower Motor Connector and wires (purple and black) going into it. Look for discoloration and/or melted wires or the purple touching metal somewhere.

Section 8A of your Service Manual will outline diagnostics - look under Blower Controls/Electronic Air, though it usually calls for the use of a Bi-directional scanner - something the Dealership should have used when it was in the Shop. If you want to check the voltage inputs/outputs to/from the Module, then at Fan 1 there should be about 2.5 volts on the Brown Wire and about 4 or 5 volts on the Purple. At 10, the input should be 6 volts and the output 12 volts. Red or Module Power should have battery voltage (though with the fuse blown, it obviously doesn't).

Sun Load and Outside Air Temp sensors are overriden at Auto 60 and 90 and there should be MAX blower at these inputs.

If you need a new Blower Module, it's used across the line - Buick, Caddy etc - or NAPA has a stocking number.

Tinting isn't nearly as effective as simply putting the solid color roof panel on your Vette.

SOF Vette

Thanks everyone for taking the time to help.

SunCr-
HOLY SMOKES what a terrific and informative answer. This is exactly what I needed and will work on it today.

BTW-I DO have the solid roof

Again my thanks. I'll update when I have some results

SOF Vette

FF1wms

Does the fuse still blow with the new blower disconnected?
If it doesn't, Take that "new"blower back and get another one.