my 1999 ram with 360 magnum has a problem.
the ac compressor was cycling on-off every couple seconds,so i got a kit from auto zone and filled it per directions. it blew cold for a couple minuets, then the ac clutch disengaged and wont engage again.this happened last nite. i tried it this morning, and the clutch cycled on/off like it did before,but no cold air. tryied filling it again, and the clutch stopped working again. jumping the switches on the compressor does not engage the clutch. any ideas as to the problem?

 

Evaporator core is most likely leaking(very common,as is heater core). Without the proper test equipment you wont find the leak.

 

Agreed.

Shop labor to remove and fix a core in the dash, be it evap or heater, is gonna be somewhere in the area of $1,500. To do it yourself is an option...but it's an all day affair even if you're good and even then you'll likely break something else while doing it.

Those cores are at the top of my list for horrible jobs. I would rather deal with a blown engine than changing an evap or heater core in these trucks.

 

I have no problem changing the heater core or evap core. My problem is giving advice to people that don't have the right equipment. I have that equipment to find the problem first. Then I can fix it.

 

the system seemed to still have pressure-30 low side,100-150 high side.if it was a leek i assume it would be empty?

 

These symptoms seem to be fairly common of late..... Must be the heat.

Jumper the low side switch, see what happens. Watch your pressures though, if high side starts approaching 300, turn off the a/c.

 

And the compressor cycling on and off is normal. If it continues to run constantly or obviously does not run at all...then there is a problem. Far too many people tend to go to FLAPS and listen to a store clerk with no experience tell (sell) them refrigerant kit and then they overfill......

 

My compressor runs constantly, blowing cold air for maybe 20 to 30 minutes then gradually just goes warm. Just trying to get an idea what's in store to fix. A shop tested and recharged it in May and won't warranty any vehicle over six years old. now it's July and in the 90's. Is the relay for a/c clutch suppose to be hot?

 

Is the compressor still running as it warms up? If it is, may be the blend door, and not the refrigerant system at all....

 

ok,when you say "jumper" the switch,do I have to leave it plugged into the connector?I have been assuming I unplug it and jump the connector,not the switch itself...