2002 Dodge Ram 2500 V-10 Climate control


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Old 05-16-16, 12:57 PM
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2002 Dodge Ram 2500 V-10 Climate control

Having a problem figuring out the climate control on the truck. I can be driving with A/C on and push on the brake pedal. I hear a pop and the temp immediately
goes warm. I shut off the controls, wait 15 seconds and the system resets back to cold. I have replaced the control panel with no luck. Any ideas??
 
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Old 05-16-16, 03:32 PM
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Will it happen if the car is in park? Do you hear a pop if the AC isn't on & you step on the brake? While it sounds like an electrical problem, the power booster sucks air from the manifold. Does the idle seem a little higher than normal?
 
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Old 05-16-16, 04:10 PM
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Agreed. The climate control doors operate on vacuum, as does the brake booster, so I would suspect that the noise you are hearing ia the door closing, and that the a/c isn't necessarily shutting off, but the flow is being shut off to the cockpit. It could be something like an intake manifold leak, not uncommon, or it could be as simple as a worn or damaged vacuum line. For starters, I would turn the air on, don't touch the brakes, move the control that adjusts where the airflow is directed, and see if you hear any familiar sounds.
 
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Old 05-16-16, 04:19 PM
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I know this problem well. There is an inline vacuum check valve that allow the vacuum to be pulled from the vacuum canister and held there. Your check valve is defective. I have a whole box of detective check valves.

You may need to go to the dealer but that's what you need.

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Old 05-16-16, 06:50 PM
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I had a strong feeling that it was a vacuum problem.
 
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Old 05-17-16, 05:05 AM
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I've tried to get it to do it in park but doesn't do it. Only if I am driving and step on the breaks. Then it pops like the door is closing hard and then goes into heat. I stop the A/C for about 15 seconds and then turn it back on and it is back in to the cool mode
 
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Old 05-17-16, 05:08 AM
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Where is it located? I'll definitely get one.
 
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Old 05-17-16, 05:19 PM
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Follow the small vacuum lines from the engine to the HVAC area. You may find two 1/4" lines tee'd off. It should be near the rear of the engine on the passenger side.
 
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Old 05-21-16, 12:26 PM
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Check Valve

Hi all, Replaced the check valve and didn't make any difference in the problem. Any thing else I can look for. Thanks all for the help.
 
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Old 05-21-16, 02:35 PM
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That check valve is a common cause of your problem. That check valve traps the vacuum in the vacuum storage canister so that when you hit the brakes.... the vacuum is not sucked out of the canister taking the vacuum away from the HVAC system.

There will be what I call a vacuum road map on a sticker in the engine compartment. That will show all the vacuum lines.

Just curious...... if you shut the engine off and wait 10 seconds..... move the mode control and see if any doors move. You should be able to hear the movement of them.
 
 

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