What are Common A/C and Heater Problems?

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Trenton

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So my climate control system doesn't properly work in my truck. The temperature is stuck on cold and defrost. I might be moving to Colorado for a couple months and I'm planning to overhaul my complete climate control components before I do so. What are common components that go out on '95-'98 Chevy trucks? I'm already going to replace the blower motor resistor, climate control panel, and the upper heater core housing. Any further ideas would be appreciated.
 

studigggs

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Blend door, fresh air door and floor/dash/defrost door actuators go bad. They are cheap and easy to replace.
 

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the freon recharge schrader valve leaks with age, replace that o ring before recharging the system
 

PlayingWithTBI

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while you're doing all that, flush out the heater core with a garden hose both ways.
 

Elroy

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my 96 sub sometimes wont produce heat, i found that i can remove the vvacuum line from the valve and i get heat, i assume there is some type of vacuum valve controlled by the knob on the dash? i think i saw something on the firewall that the vacuum line led to but it was too cold to mess with it at the time
 

delta_p

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Blend door, fresh air door and floor/dash/defrost door actuators go bad. They are cheap and easy to replace.

What's the best way to replace the fresh air door actuator? The one up under and behind the blower. That's the only one i hadn't replaced yet because it was harder to get to than the other two.
 

east302

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my 96 sub sometimes wont produce heat, i found that i can remove the vvacuum line from the valve and i get heat, i assume there is some type of vacuum valve controlled by the knob on the dash? i think i saw something on the firewall that the vacuum line led to but it was too cold to mess with it at the time

When you select the “max” cold detent on the temperature dial, the solenoid valve on the firewall energizes and vacuum is applied to the heater valve. Feel the bottom of the valve, there is a spring loaded rod. When vacuum is applied, the rod goes in (up) and closes the valve to block coolant flow into the heater core.

This is meant to maximize a/c performance. If pulling the vacuum line from the valve lets it open, then the heater valve is good. That means that the solenoid valve is either constantly energized or is stuck open and is applying vacuum regardless of the panel dial setting.

It’s either a bad solenoid or an issue with the AC panel. The solenoid connector has two wires. Disconnect it, put a meter across the two pins and see if you get 12V with the dash panel -not- on max. If so, then it’s probably the panel. If not, then the solenoid valve is stuck open.




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Trenton

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my 96 sub sometimes wont produce heat, i found that i can remove the vvacuum line from the valve and i get heat, i assume there is some type of vacuum valve controlled by the knob on the dash? i think i saw something on the firewall that the vacuum line led to but it was too cold to mess with it at the time
I don't know if I'm supposed to, but my truck has no heater valve. I looked it up a while back. Both heater hoses go straight from the water pump to the heater core.
 

studigggs

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What's the best way to replace the fresh air door actuator? The one up under and behind the blower. That's the only one i hadn't replaced yet because it was harder to get to than the other two.

I used a mini ratchet. tight space, but you can do it without pulling anything. three screws. Make sure you get the right actuator. I believe up to '90 (AC w/o 'max air' button) they had 5 pins whereas the later models with the 'max air' button had different pins.

https://www.amazon.com/Neiko-03044A...8&qid=1549943546&sr=8-5&keywords=mini+ratchet
 
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