The A/C seems to be doing its own think now.

It will be working fine then it stops. The air will start to get warm and after several miles (maybe 6 to 8) it will start blowing cold air again. This will work for 15 or so minutes and then do it again.

Checked pressure - it was ok. Compressor rotates freely, nothing unusual noted.

So any ideas? Relay? Sensor? or ?????????????????

1998 Dodge Ram Quad 5.9L

Let me know what you think.


Thanks,

Michael

 

Sounds like the compressor is cycling, which would mean the pressure is right in the gray area of being too low and having just enough pressure.

 

Yes, if it turns on, then off, then on, then off...etc...
thats a sign of low pressure.

recharge...

I am getting my system flushed and leak checked. I called around and found that with the age of the truck, it should get a flush since it can settle and clog the cooler.

 

no, itisnt cycling.

it will run for an extended period of time and then just cut off.

it will stay off for probably 10 to 15 min and come back on, that is why i thought it might be a relay or something.

thanks

 

There is no SET time for cycling! Put a jumper across the low pressure plug and see if it stays on longer, if it does you'll know it needs to be recharged. Just don't leave the jumper on too long because then you could damage the compressor. Of course it could be just a loose or dirty connection at the low pressure switch plug.

 

if the compressor runs with the jumper wire in thats good you dont need a compressor, if you add the refrigerant and it doesnt cycle ( refrigerant sensor plugged in) check the sensor itself, have seen it before on a 96 ram

 

Make sure when you measure the freon level you take into account the ambient air temp outside. Those little gauges that say you're fine are set for 70 degrees ambient temp. If it's hotter outside you should actually have a higher pressure. There's a chart in the FSM that states what pressure your low side pressure should read at specific outside temps.