Kolenc

I have a 2012 express 3500. The heat is on all the time and the controls don’t work including the fan. I tried changing the heater resistor but that did nothing. Do I need a new climate control module?

mountainmanjoe

you need to do more troubleshooting. Start with fuses.

Kolenc

I checked all the fuses

mountainmanjoe

what else?
Did you test the blower motor?

Kolenc

It was intermittent where everything work and than everything stopped at once. When it happens like I said. There is heat coming out of the vents even though it is in the off position. When you try to turn it on nothing changes even if you set temperature to a/c and fan doesn’t work. One time I pulled fuses and unplugged the resistor and all of a sudden it worked for about a couple weeks. Now it hasn’t work at all again which is why I tried changing the resistor.

mountainmanjoe

maybe the high speed relay welded itself shut. Try giving it a whack.

Kolenc

My van doesn’t have a high speed fan relay. I rechecked the hvac 1 and 2 fuses and they are good

mountainmanjoe

it does have a high speed relay. It's part of the resistor assembly.

Your question is still unclear to me. when you say "The heat is on all the time", do you mean the blower motor won't shut off?

Kolenc

The control on the dashboard is off but heat comes out of all the vents and the blower is off. The a/c or heat **** does nothing either. I bought a new blower motor resistor and nothing changed. The fan does not work either

mountainmanjoe

Oh then you have the same symptoms as this guy a few days ago:
https://chevroletforum.com/forum/exp...orking-114608/