Okay so I installed a new heater core in my truck not to long ago. Had the ac drained and installed a new acculmator. Vaccumed it down recharged with what the cart said was two pounds, now the ac will not come on. It held 28lbs of vac no leaks charged easy put one ounce of oil in when recharged. So what could it be keeping it from kicking on? It will sometimes kick on for one second then shut off. It is still hot here in GA, but most of all i want everything to work on the truck. Thanks Shawn C.

 

Quick check, take the low pressure switch connector off ( don't remember exactly where it is at, usually on the accumulator ) and run a jumper between the contacts. That should allow the AC to be turned on. If that works, it is either a bad low pressure switch, low system pressure, or the switch not reading, you did say you replaced the accumulator?

I am assuming it worked before the heater core?

 

I had to replace it thanks to a friend....... Thanks JJ. But you know i also tried to let some pressure off to see if it would kick in but no luck. I will try the switch

 

You really need a set of gauges to know where you are at, below 25 PSI it shuts the Compressor off to save it.

Post what you find and we will try and help more.

 

When it did kick on it did drop below 25 on the low side but then it jumped up to 78 and did not kick back on