'05 Dakota, Laramie w/4.7. If I have to accelerate hard ( shove my foot in the radiator) the air cuts out. If I turn it off, wait a few seconds then tun it back on it restarts. It only started happening the last few days.
Ideas?
Thanks, Bill

 

Get the pressures checked.

 

OK,I had the pressure checked this morning but its acting the same before. When had it idling for 45 minutes the temp checked at the vents was holding at 55 but during the test drive the air kicked out even if I accelerated normally but would start again on it's own maybe 15-20 seconds or so later.

Bill

 

When you say "kicked out", do you mean the blower fan stops blowing, or it just starts blowing warm air?

I believe the A/C system is designed to disengage the compressor upon hard acceleration, but there's almost certainly (normally) going to be enough "residual" cold refrigerant in the evaporator under the dash to keep it blowing cold for those few seconds of acceleration.

 

The blower continues blowing air, just warn air. If l let it idle and rev the engine while parked it cools normally but when driving it will switch between cool and warm. If I turn it off, wait a few seconds turn it back on it restarts or at times it will just restart by itself.
BTW, no DTCs or pending DTCs

Bill

 

Hmm...Did you happen to install an electronic engine cooling fan?

 

No, I haven't done a thing to it since new.
This just started a week or so ago. Reading through the shop manual two of the possible culprits "may" be the ambient air temp sensor or the A/C pressure transducer but that's only a WAG.on my part.
If it were the pressure transducer I assume it would have thrown and stored one of two DTCs, P0532 or P0533 but the pending code list was clear and the check engine never came on. I haven't figured out how the ambient air temp sensor comes into play as of yet., I have to study it's function a bit more.

The best idea I've had so far, I'll make my wife drive the truck and I'll drive her car!

Bill

 

I would assume it shouldn't have anything to do with the pressure transducer, because it functions independently of vehicle speed or shifter position...It would operate just the same while the system pressure fluctuates whether revving in Park or moving.

The ambient air temp sensor, mounted in front of the radiator, is closer to the outside air flow and maybe took a hit from debris? (Or a loosened wire connector?)

There's also the A/C clutch relay, located in the fuse/relay box under the hood...Maybe it's becoming worn out and, while working ok in Park or other non-accelerated conditions, stops working properly when it gets accelerated or "feels" other non-stationary physical forces?

My gut is telling me the problem has something to do with the physical forces upon the truck (acceleration, deceleration, turns, bumps, etc) such as either a loose wire connector, or a failing A/C clutch relay as mentioned above, rather than a failing electronic sensor which is generally speed/acceleration independent in operation with regard to the A/C system. And if the problem was the ambient air temp sensor, you'd probably feel engine performance problems also, because that sensor helps to regulate engine operating parameters.

 

First of all thanks for your help!!!!
I'm of the mindset like to solve problems on my own not to mention being a cheap old goat. The last time I need the dealer's intervention it cost me $462 for a water pump including a new belt and winterizing and then only because I was too stinking lazy to do it myself.

Thanks for clearing up the air temp sensor operation. I'll take a look at it for any indication of damage and or any corrosion on the connector-pins and replace the clutch relay.
They only cost a few bucks and NAPA has both in stock so its probably not a bad idea to replace both anyway with 78K on the clock. I grab and replace them sometime this afternoon and report back.
And once again, Thank-You!

Bill

 

No prob. If you're going to replace the air temp sensor, I would only replace it with OEM, not aftermarket. These engines don't seem to react well in the long-term to any aftermarket electrical sensors/modules.