I have a 95 dodge ram 3500 cummins. I am experiencing a wierd a/c problem. It started out by not cooling well at an idle but as soon as you take off it would cool good now it cools good on the highway for about 40 minutes then the blower starts to shut down I found that the heater box under the dash at the blower is turning to a block of ice and the dryer is iced up and so is one of the lines. The ac compressor wont disengage no matter what you turn the switch on the dash to. The compressor is not cycleing it just running continueous. I was wondering if this has a high pressure switch that might be giving problems. The only way I could shut the ac pump off was to unplug it. Help me please by the way the system has never been serviced or worked on at all the truck has 560,000 miles thats pretty **** good for the original system but I need help please

 

I was working on a truck last week that the compressor wouldn't disengage it was the compressor clutch. Ordred new clutch kit for about 100.00 even came with new coil.

 

That could be a possability but there are so many other problems with this a/c unit.Thanks again

 

My guess would be the pressure cycling switch on the accumulator or someone jumperd across it.

 

No one has jumped across anything. I am the only person to work on the truck. would the switch your talking about like a high pressure switch would that be the item to make it cycle properly? Thanks for all the help