Ram 1500 A/C question

StewartFan20 · #1 05-28-2006, 07:46 PM

Hi all, I borrowed my father in laws truck the other day and the a/c was cutting out up steep hills under load. It also does this if the throttle is pushed down to pass someone. He said it has been doing this since he started using it this spring. Im not familiar with dodge so I wanted to see if maybe it was something other dodge owners have encountered. I believe its a 96-97 year model.

scoutinkeith · #2 05-30-2006, 08:39 AM

this is verry common with dodge trucks.
there is a TSB about changing the check valve in the vacume line that supplies vacume to the controler for the heat/ac, that is supposed to take care fo the problem.

StewartFan20 · #3 05-31-2006, 10:17 PM

Sorry for my ignorance but what is a TSB? Some kind of service bulletin? I was hoping he might get lucky and it be a recall deal.

scoutinkeith · #4 06-01-2006, 08:07 AM

yes, TSB is short for Technical Service Bullietin.
I don't think there was a recal for it, but you could always check at the dealership, just give them the vin and ask if there are any open recals for it.
at any rate, I think the new check valve is only a few dollars from the dealer, and is really easy to change.

89ltd · #5 06-01-2006, 11:26 AM

do you guys know about the a/c cut out switch, when passing and under heavy load the a/c compressor shuts down to give it more power. Thats the way it was designed.

dennyge · #6 06-01-2006, 02:32 PM

I have had this exact same problem on my 99 1500. I was told in a previous thread that it is most likely a small vacuum leak.

89ltd · #7 06-01-2006, 03:13 PM

its only been that way for 30 years now.............

dennyge · #8 06-01-2006, 04:56 PM

I would be willing to bet that if you reproduce the problem again, you will find that the air is being re-routed to the defrost vents instead of actually cutting out.

scoutinkeith · #9 06-02-2006, 09:33 AM

I'd have to agree, I still think it's a vacume problem too.
that A/C cutout switch should only disengage the clutch on the compressor, you should still have air coming out of the selected vent in the cab.
however, a vacume isue will cause the vents to switch to the "defrost" setting, and if the fan isn't on verry high, and without puting your hand over the defrost vents, it would be easy to think that the ac had shut off.

StewartFan20 · #10 06-02-2006, 04:29 PM

Thanks for all the tips everyone. I will be visiting them this weekend just to be absolutely sure but I believe the air was coming out of the defrost vents some when this happened. I could be wrong but I believe this was the case. I will check all the vacuum lines first to see if I can find a small leak or if the lines are in need of replacing. If not, where is the check valve located just in case it needs replacing? Can it be replaced without any loss of freon?

scoutinkeith · #11 06-05-2006, 08:09 AM

yes, the check valve can be replaced without loosing any refrigerant, the refrigerant lines are compleatly seperate from the vacume lines.

I'll have to do some looking to make sure, but if I remember correctly, the check valve is on the engine side of the firewall, located neer where the vac line goes through the firewall.

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