AC light blinking??

I've been dealing with this all summer. My AC blows cold as long as the truck is idling. But as soon as I eccelerate, it starts to blink. I can press the button twice (off and back on) and it blows cold again. Sometimes it will blow cold for 20 minutes, sometimes 20 seconds. I replaced the relay but it's still doing the same thing. I took it to a shop and they said I needed a new expansion valve and dryer. It that were the case, would I still get cold air while idling? I hate to spend the $800 if that's not my problem. Any suggestions??

 

when i cross deep water my compressor stops and the "ac" light blinks, when i get out of the water i just press it twice to turn off then back on and it stays on, but it never does it unless i cross water for some reason

 

The blinking is to tell you that there is an issue with the A/C system. It could be cause you're low on R-134a or your compressor is locking up. You need to have the system checked out by a qualified mechanic.

The expansion valve could be the problem, but not likely. The expansion valve regulates the amount of r-134a that enters the evaporator, so at higher rpms the compressor is putting out more pressure and the expansion valve may not be opening/closing enough to keep the evaporator cool. IMO if they say it needs it and they replace it and it doesn't fix it, it's up to them to make it right at no extra cost to you. At least that's how they do it at the shop I work in.

 

I just had a all new system put in summer before last. And I've had the system evacuated and refilled last month so I know it's not low. And it will freeze you out if it's sitting still (idling)? I guess I need to get a second opinion from another shop. Thanks.

 

Same thing happened to me when I bought my truck used....relay didn't fix it and they replaced the compressor clutch and its been normal ever since. Good luck!

 

That was actually what I was thinking it was. I'll check that next. Thanks

 

Same thing happened to me last year as well and it ended up being the AC Compressor & AC Clutch... It wasn't a cheap fix but thankfully I had a transferred extended warranty from the original owner and it didn't cost me a dime. If that wasn't the case, The bill was around $1,500 if I recall with parts/labor. Good luck!