HELP! My 1998 Ram van 1500 is sputtering or hickuping for about a fraction of a second while I'm traveling down the road with the air conditioning on. It happens seemingly at random and doesn't matter what the speed is, it's happened at 30 Mph and at freeway speeds. At first I thought that it was doing it all the but after replacing the plugs, plug wires, PCV, and cleaning the IAC, I noticed that it was only happening when the air conditioning was on.

It's a 1998 Ram 1500 Mark III conversion with the 3.9l V6 and a 3 spd transmission.

Thanks for any help!

 

The only idea I can come up with, is that the wiring that goes to the compressor clutch is bare somewhere and randomly touching ground. This would cause a momentary drop in electrical power, which in turn would drop out power to the ignition. Not being a solid short and only being momentary, would also explain the fact that no fuses have blown...yet.

 

Thanks for the advice! This one had me stumped, I'll try your advice as soon as I can and let you know.

 

I wonder if it may be that the AC compressor is momentarily locking up but right now able to free it self as the engine bogs down. I have seen this on a GM pickup that did this just before it fully locked up.

 

You would think that the belt would snap under such stress.

 

Yes, but it never did. When the AC finally locked up the belt squealed really bad but has not broke to this day, nor does it show any abuse.

I did remove the plug from the compressor and tied it up safely.

 

I still haven't looked at the wires yet....darn work thing getting in the way!

I don't think that the compressor is freezing up, as it doesn't happen when I'm sitting at idle with the AC on. It only happens when I'm traveling down the road. That's why I originally thought that it was a fuel problem under load, until I realized that it wasn't doing it w/o the AC.

Who knows, I've been wrong before. It will definately be something to check if I can't find a wiring problem. Any Idea how to test the compressor?

 

About the only way to test is to use the AC gages that connect to the system and see what pressures are being ran. Also see if the high side pressure is steady or bouncing around, that would be a clue that there is a problem.

You want a steady reading not a bouncing one.

 

Well, No dice on finding a bad wire on the compressor clutch. I spent two hours checking everywhere that I could think of and no luck.

I guess that I'll take it in and have it checked to see what its doing...I hate to let someone else mess with it....