• Welcome to The Truck Stop! We see you haven't REGISTERED yet.

    Your truck knowledge is missing!
    • Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
    • We have tons of knowledge here for your diesel truck!
    • Post your own topics and reply to existing threads to help others out!
    • NO ADS! The site is fully functional and ad free!
    CLICK HERE TO REGISTER!

    Problems registering? Click here to contact us!

    Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!

Circulation fan/AC issues

3bals

3bals

Retired Firefighter
Messages
428
Reaction score
297
Location
Minnesota
Last summer my AC quit working on my 98 K3500 6.5 TD. I wasn't too concerned, as I didn't drive it very much and if it was warm outside, I just opened the window. In the winter, it wasn't a problem.

I had noticed the compressor clutch wasn't engaging and someone told me it was probably low on freon. Now that I've been driving it more and the weather is warming up, I decided to try one of those DYI AC recharge kits. Yesterday I picked one up and read the vague directions and was able to get the compressor clutch to cycle on and off by adding some freon. I thought, great it works, but when I went in the cab to feel the air, there wasn't any flow. The fan wouldn't come on. I checked all the fuses I could find and none were burned out (visually). I really couldn't find one that looked like it was specifically for the fan either. Now, I'm not sure if the fan worked before I recharged the AC or not, because like I said when it got warm I would just open a window. But, I do know that I worked this past winter.

Now the questions are: Is there a secret fuse somewhere for the fan? Did the fan coincidently just stop working now? Did I mess something up when I recharged the AC system or am I just over looing something simple?
 
Here's an update.

I found the fan/blower problem. It was a melted connector on the blower switch. It's not focused. but you can see the issue.
plug.png

Here's what I replaced it with.
plug 2.jpg
blower switch.jpg

I have an appointment tomorrow to have the AC looked at to see why it isn't working. but the blower works fine now.
 
I would add a ground strap to the blower motor. IMO some cases of the melted connector issue is high current draw from a bad blower motor. If this melts down again I would replace the blower motor (AC Delco only as the knock off motors are louder) and get a larger gauge wire for power bypassing the connector. GM is famous for too small wiring and connection problems to the HVAC blower melting down.
 
Did you also replace the blower switch? The switch has a seperate output to power the compressor portion of the circuit, and agter seeing that connector, I would wager the switch might have gotten toasty to. If you did, the next big problem would be the low pressure switch since GM were idiots and let the switch carry the clutch current instead of using the relay like every other car out there does.
 
Yes, I replaced the blower switch and the plug kit came with some heavier wires and some lighter wires. I used the heavy wires in the slots that melted.
 
They found a bad o ring on the HP switch, evacuated it and recharged it. It works fine now.
 
You must log in or register to reply here.
Back
Top