'01 1500 A/C questions

05-08-2006, 09:27 AM
I'm working on a '01 Ram 1500 4x4 w/ a 360 and no cold a/c. The compressor cycles about 2 seconds on and about 10 sec off. When its on, it makes a wierd noise in the interior like a phone ringing in a pocket or something. I thought compressor bearings, but its quiet when you're up next to it. I removed the refrigerant and removed the discharge line from the evaporator near the firewall to inspect the F.O.T for metal contamination. Upon removal of the line, I was surprised to see there was no FOT there. Do these trucks use something other than a FOT or TXV? I'm not used to Dodge, so any help is most appreciated. Thanks. Oh, one more thing, It clunks going into reverse, but not bad enough that it would bother me. But this guy is complaining about it, so where should I look first? I've never driven a Dodge that didn't make this noise, and its quiet accelerating, cruising, and decelerating. Thanks again

05-08-2006, 05:08 PM
If its kicking on and off or what you would call "short cycling", its because of one of two things. The compressor has a low-pressure switch and is kicking on when the thermostat is activating the start windings on the compressor terminals and when it cranks up the low pressure switch kicks off, the system 1. could be low of 134a refridgerant,run between 25 and 32 pounds or whatever your truck requires, 2. could have a restriction somewhere in the system, maybe in the liquid line dryer or the a moisture build up in one of the line sets due to a leak or past leak in the system that never was evacuated fully. Now hear me this, you may know or not know, but before you fill it back up again make sure you pull a deep vac on it to rid the system of that moisture, you never know it might fix your problem.

05-09-2006, 10:59 AM
Every time I've had a vehicle with a rapid cycling AC, adding coolant to the system took care of the problem.

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