Ok, so i have 1996 ram 1500 5.9l v8 4x4 slt laramie...the other day i was driving and the engine wouldnt get up to speeds very easily and i noticed my RPMs wouldnt drop below 2000 once i was at 40-45 mph...and when i would let off the gas the rpms would go pretty much dead and the truck would decelerate from 40-45 to 30 almost immediately. and i got to thinking the only thing i have done differently is turned the vent selector **** to the "off" position a couple days before. so at the next red light i turned the **** to just the defrost mode bc thats what is usually at... and the truck is running like new again...rpms are normal at 40-45 they dont really exceed 1500 like usual, any suggestions on what it might be or if anybody has encountered this problem before????

 

That is truly strange. Heater being off should NOT effect how the engine runs. I would actually expect it to run worse with it ON, in the event of a failing charging system...

Only thing I can think of is, somehow, your blower motor circuit is providing ground for one of the engine/trans circuits, finding which one is going to be truly fun....

If you turn the vent selector to the off position, with the fan off, how does it run? Any change when you turn just the fan on?

 

im sorry, the vent selector was in the off position when this all happened...fan dial is always set to the middle (off?) when i am driving bc the a/c doesnt blow cold. but when i changed the vent selector to defrosting, upper body, lower body,etc... the truck was running fine after that.