I really dont use my a/c all that much, but when I do I put it on high and it really doesnt seem to blow that well. It has the digital/electric a/c controller and on setting 10 for the blower, it only blows about as hard as my truck does when I have the truck set to 2. Is this common for our vettes or is there something I might have to replace. Thanks for any inputs.

Dave

 

My center vent used to not blow hard even on high fan setting, until I took it apart and removed that rectangular foam gasket thing-- it had apparently deformed over the years and was partially obstructing the flow.

 

I just read another post about someone's a/c stuck on high, something about the resistor maybe bad. If that is the case, is it possible that there is a resistor for the low and high settings for the a/c blower and that maybe a problem. I just hope that the a/c can blow harder than it does because I can barely feel it from any of the vents unless I hold my hand about 6" from the vent.

 

Mine (95) doesn't really blow that hard either. But after a short time (15-20 mins) its cold enough inside the car that I will turn it down. This is in 90+ temps here in FL. So I don't worry about it too much.

 

Worked fine when I bought it, haven't tried it since.

 

Sounds like you have the "C68" climate control. This system does not have any resistor pack. It's got lots of electronics to control the fan instead. Your problem is probably in the dash. I have the Helms sections for this system pdf'd. PM me with your email address, and I'll send them along. Of course, if you pick up your speed, the air will blow in better too.

 

Jumper the blower motor to the Battery and see if it's better. If not, the duct work may be leaking (it's sealed with foam that deterioates with age) or the Evaporator is plugged up (from the Factory, the intake side has a foam filter and if it's leaking, the foam turns it into a gooey mess).

Check the blower motor wiring. If it's discolored, it's dropping volts. Take apart the the weatherpak and solder the crimped leads.

Blower motor speed is controlled by a module (amplifier) mounted on the Evaporator Casing. The brown wire is the input signal from the dash assembly and it has an operating range of 2.5 volts (Low) to 7 volts (Max). Output is the purple wire and it's range is 4 volts (Low) to 12 volts (Max). You should measure the output at both the Module and the Blower Motor Connector.

All GM Electronic A/C systems monitor the output voltage (Purple) with a spliced fused circuit back to the Control Panel. If the fuse opens, it will default to Max Blower at all times.

 

GREAT info! Your post should be added to the "Sticky" thread above...

FWIW, my A/C doesn't blow as hard as I expect it to when it's on 10, but like someone else mentioned, within a few minutes, it's plenty cool inside the cabin.

 

Mine blows pretty well and gets cold fairly quick. But I would expect it too. The system was just overhauled a couple of years ago...

 

You're '96 is a tad different in that the Dash Assembly signal is sent to the Programmer (on a Data Line, so absent a scanner, it's difficult to diagnose the Dash Assembly) which then interprets it and sends the blower signal to the Module. The wiring at the Module should still be Brown or Tan for the input and Purple for the output as GM has pretty much used this color coding forever (but whatever color is at the blower motor should be the same at the Module). Testing of the Module Inputs and Outputs would be the same. Either system, when in "Auto" mode, is going to control blower speed based on the inputs from the Inside and Outside Air Temp Thermistors - except at 60 or 90, when it should overide the Sensors and blow at Max. At least through '89, the only way to get Max Blower was at the Auto 60 or 90 setting. Manual 10 was a tad less, so for diagnostics, I've always used the Auto 60. I also think that the 5amp fuse protecting the Return signal from the Output line is moved to the underhood fuse panel for your Year. Prior to '90, it was a stand alone on the firewall to the left of the Evaporator Case, but you don't need to be concerned with it unless it's blowing at Max at all times.

 

I think that is my problem, I just need to speed up and get more air into the car.
Thanks Suncr for the info. My e-mail is dg_86@yahoo.com and again thanks.

 

I threw mine away! LOL

 

my 93 blows hard and cold, after a few miles i normally have to turn it down. not sure what could be going on with yours