153cwg

99 ram 2500, while driving transmission wants to down shift. up down, up down, rpm only goes up 2-4 hundred rpm please help, seems to be getting worse

pind

Governor pressure solenoid sticking, causing a hunting condition.

Check line pressure while driving, it will tell the whole story.

BigIron70

At what speed? Possible RFI noise causing trans to come out of lockup. Generator and/or generator wiring harness may produce excessive radio frequency interference (RFI) which can interfere with PCM input signals. Check main ground circuit for the PCM. I would also run separate ground from battery ground direct to the PCM. Repair loose or corroded connections. If dual batteries verify batteries are properly matched and are in good operating condition.

153cwg

Thanks I was just reading that it be an electrical issue. This is my 1st Deisel and have owned it for three weeks now. A post said to disconnect the alternator output wire and see if it still happens.

153cwg

Ok so the saga continues. Today I cleaned the air filter its a k&n. Took truck for a ride and no down shifting seemed to run fine. So now I have two questions (did I say its my first diesel) could the shifting down and up be due to the horrible air filter? The second is what rpm should I have at cruising speed say 65mph? There is one major difference between today and when the shifting issue occurred it was about 35 degrees warmer today.
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bill50cal

with that amount of RPM change it will be the torque converter clutch (TCC ) shuttling in and out. it CAN be caused by an alt. going out ( AC noise ) your second post say'd it did not do it after you did some work on the truck BUT the temp's was 35 deg warmer = less grid heaters, if the load on the alt was less it will act up less. try it with a high load on the alt. turn on EVERYTHING electrical AC, blower on high, lights and try it again. if it gets worse disconnect the SMALL wire on alt and try it again.if it goes away with alt unhooked that is your trouble. there is also several fix's to help eliminate this trouble. do search for torque converter shuttle.