'95 C2500 Temperature Control Assembly issue

[Raymond Dawson]

I just purchased and replaced the Temperature Control Assembly in my son's '95 C2500. The issue with the old one was that it cut off once you moved the knob past the second indicator. Once replaced with the new one, it wouldn't work at all. Then, it started working but now if you turn the knob to high, it shuts off.

Can anyone assist with this? My first thought was that it's low on freon but I'm not that familiar with the A/C/Heater systems on these trucks.

Thanks,

Ray

 

[99'Subourbon]

Could be the blower resistor, or in my case, loose wires. Check for wires grounding out somewhere, and/or make sure they are fully seated into the terminal clip.

Usually when the resistor goes bad, high only works.

 

[jkeaton]

I just purchased and replaced the Temperature Control Assembly in my son's '95 C2500. The issue with the old one was that it cut off once you moved the knob past the second indicator. Once replaced with the new one, it wouldn't work at all. Then, it started working but now if you turn the knob to high, it shuts off.

Can anyone assist with this? My first thought was that it's low on freon but I'm not that familiar with the A/C/Heater systems on these trucks.

Thanks,

Ray

Being low on refrigerant (they don't use, or call it Freon anymore) would not cause the blower not to work. I assume you are referring to the blower motor only. So, at first the blower would not work at all and now it only works if it's not on high, correct? As stated, that sounds more like a blower resistor issue instead of a control panel issue.

 

[Raymond Dawson]

Forgive the ignorance, where is the blower resistor and how would I check to see if it's bad?

 

[99'Subourbon]

I am not 100% sure on your truck, but on 96+ OBSs, it's behind the glovebox, ontop of the blower motor. The glovebox is removed pretty easily - 2 top tabs (which act as stops for the glove box when its open, from dropping to the floor) squeeze towards each other, allowing the glovebox to fall forward. If that makes sense.

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Number 74 - its' held down with 2 7mm screws. Area is tight, a ratcheting short length 7mm wrench works best.

Here is a video as it relates to 96-99 OBSs:

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[Raymond Dawson]

Thanks a lot. I'll look into it when I can get some time...

 

[99'Subourbon]

Once you've disconnected the terminal from the resistor, you can check if your control module is bad by going through each fan speed and check at the terminal for power. If that's good, then next would be your blower... but since you stated it does turn on, that rules it out too. All that's left is the resistor. So either it is bad, or you are grounding out somewhere.

Ideally, it isn't the latter - wire gremlins are a *****.