[xwind11]

of 1998 dodge ram 1500 when I cut the AC on it blows cold for about 20 minutes then it starts to get hot not like the heat on justno cold and kinda smell a moisture smell very light could just be the temp change in the truck. So then I cut it off for about 30 minutes and back on and it blows cold again for about 20 minutes. when i bought it the needle valve in the low side was bad so it had no freon in it but i fixed that and filled it up.

Thank you

 

[Excoastie]

keeping in mind that I'm not even close to being an AC expert it sounds to me like your condenser might be freezing up.

When it starts to not blow cold next time, stop and check out the components of your AC system... look to see if something is icing up.

just my guess

Exco

 

[RansRAM]

of 1998 dodge ram 1500 when I cut the AC on it blows cold for about 20 minutes then it starts to get hot not like the heat on justno cold and kinda smell a moisture smell very light could just be the temp change in the truck. So then I cut it off for about 30 minutes and back on and it blows cold again for about 20 minutes. when i bought it the needle valve in the low side was bad so it had no freon in it but i fixed that and filled it up.

Thank you

I use to work in after market A/C several years ago. Not an expert however I agree that something could be freezing up. Could be an expansion valve problem. You should have some gauges put on to see what the low and high side pressures are doing. When the compressor is running you should see approx 30-40 psi on the low side and around 150 psi on the high side. I's very important not to overcharge the system.

 

[Toms Blue Ram 1500]

Could be over charged also .