A/C blower issues

[CaliDude76]

Ok... need the experts in here advice. The other day I went to use the a/c and the compressor engaged but it was only blowing on the lowest setting, no matter what setting I put the fan toggle switch. Fussed with the mode setting a bit then boom... it went to hi and worked like normal...
Did it again this morning but worked again.... am I looking at a new head unit or maybe a bad relay????
Any help or suggestions please
Thanks!
Calidude

 

[89Suburban]

Mine did the same thing and it turned out to be the heater fan speed switch. There is also a switch on the top of the heat/ac mode controls. If you pull those out and take a quick look at them, you can easily see if they are burned up or not.

Here is a few pics to reference for ya.

http://www.gmsquarebody.com/forum/showthread.php?t=403&highlight=switch

It could be other things too, but I would start at those two switches.

 

[CaliDude76]

Mine did the same thing and it turned out to be the heater fan speed switch. There is also a switch on the top of the heat/ac mode controls. If you pull those out and take a quick look at them, you can easily see if they are burned up or not.

Here is a few pics to reference for ya.

http://www.gmsquarebody.com/forum/showthread.php?t=403&highlight=switch

It could be other things too, but I would start at those two switches.

hmm.. I might just do that, I was thinking maybe the resistor, or that relay that is mounted on the Evap Boot under the hood.. I was hoping not to have to crack into the dash... but If I have too....

It works fine now... I'm wondering if it's just bad contacts or something.. it is pretty dusty out on my job.

wondering if I could buy those relays and fan switch at my local AutoHouse

Summer here would SUCK with no A/C!!!! we're pushing 100 out here this week

 

[89Suburban]

My fan switches high speed prong vas visibly burned, and when I took the switch apart you could really see the damage. First thing I was thinking was the resister group too that's mounted in the blower housing under the hood, but I checked it and it was fine.

Auto Zone has it on line, not sure about your local stores, you will have to call around. AZ wants $11 for it.

http://www.autozone.com/autozone/pa...omString=search&itemIdentifier=184481_0_3319_

I would definately pull it out first though and check if it is burned before spending any money, you could always uses a jumper wire in the mean time in the switch plug until you get the part, that is what I did.

 

[CaliDude76]

My fan switches high speed prong vas visibly burned, and when I took the switch apart you could really see the damage. First thing I was thinking was the resister group too that's mounted in the blower housing under the hood, but I checked it and it was fine.

I would definately pull it out first though and check if it is burned before spending any money, you could always uses a jumper wire in the mean time in the switch plug until you get the part, that is what I did.

You were definately right... I kept using it till the bitter end..hoping it was just dirty contacts (I really hate cracking into my dash, a lot of my screw mounts are brittle and cracked.. half the dash screws are stripped).. ... but it finally went..

actually it stayed in either extreme high, or extreme low speeds these last few days.. when it did decide to kick on.. the middle two selections were shot.. oh well not bad for 27 years of use..

Think it was a bad switch??? LOL

 

[89Suburban]