HVAC issue help needed

[RPM Motorsports]

Ever since I got my truck back up and running, I've had issues with the system. The truck sat in the shop for 2mos, before i had a chance to swap the motor. When I turn the heat or A/C on, it will run at temp for a while. After a bit, the A/C will go warm, and the fan slows. Same with the heater, at first it works fine, then cools down and fan slows. If I turn it off for 3-5min, then back on, it will work fine for a few min and then have issues again. Any idea HVAC guys?

 

[coldLBZ]

Does your truck have the digital climate control? Does it always default to the same settings (temp, fan speed, etc)? My '08 would always default to the same temp, fan speed, etc when I was having battery/starting issues.

 

[RPM Motorsports]

Yes, it's digital. The fan speed can be maxed out, and it slows when the temp starts going funky. At first since it was summer, I thought maybe it was the A/C system thermostat thinking it was at temp and trying to maintain temp. But now that it's cold and the heater goes from hot to normal, and fan slows I don't think so.

 

[duratothemax]

You're really going to need a Tech 2 to diagnose this further.

But just for grins, did you try the "force relearn" procedure? Key on, then unplug the HVAC module (with the key still on) for 10 seconds, then plug it back in with the key still on. Let it sit there for a minute or two to recalibrate itself and see if that does anything....

ben

 

[RPM Motorsports]

I'll try that when I get back to the shop, thx Ben.

 

[i_keyser]

There will probably be codes in the hvac module. If the system recal doesn't work you will need to get the codes out of it.

Sent from my DROID RAZR using Tapatalk 2

 

[RPM Motorsports]

No such luck with the reset, looks like I'll be buying a techII so I don't need to borrow it anymore.