I searched before I posted this, but didn't find any related threads/posts. The battery in my truck would go dead overnight, and I figured it was from sitting around not being run (it had several issues when I bought it that I've been repairing.) Put a new battery in it, and the same thing happened. That was when I realized I had an problem besides the battery.....


When I connect the battery, I can hear a relay closing on the passenger side of the engine compartment. I didn't have time to pursue it further, but I'll be looking at it the morning. The heater grid relays work OK, I can hear them cycle. Truck starts and shuts down fine. What other systems use big relays besides the heater grids and the fuel shutdown? Thanx in advance....

 

I can't think of any relays on the passenger side.

 

the only relay i have on the passenger side it the relay for my ex brake!

If it was the drivers side it could be the ASD(AUTO SHUT DOWN) relay or A/C relay......don't remember what the 3d on is

If the relay click when you put the battery cable on its not the relay at fault but one of the wires from or two the relay.

HHMMmmmm just thought about what i just said

If the A/C clutch relay(drivers side fender), activated when you conected the battery,.........on the passenger side there would be a click of the A/C clutch when it snapped to gether or ingaged!!!

 

What you said, Flash...it WAS the A/C clutch closing. Gonna check the relay and wiring. Hooked the battery up this morning, clutch closed. Ran it a few minutes, turned the defroster/ A/C on and off, and shut the truck off. When I did, then hooked and unhooked the battery, the A/C clutch remained open.....

A thorough degreasing is next........stronger letter to follow.

 

Not real sure this will apply to your truck: on some Mopar HVAC systems the A/C compressor cycles on/off to control temps. Even with heat or defrost on the A/C compresor cycles. A buddy told me that if you push in the 'Heat' button and then gently pull it back out that the compressor no longer cycles! It seems to be true on my '90 Dodge W-350. I suppose another cheap fix is to cut in to the compressor wire harness and put a switch into the hot side, with toggle concealed under dash?

 

If the compressor is staying engaged.. Unplug it.. or make sure you run the blowers.. if the compressor runs without the blowers it runs the possibility of liquid refrigerant getting back to the compressor and damaging the compressor.. the accumulators supposed to stop this.. but if there's no air flow accross the evaporator.. sometimes there is too much, and some gets to the compressor and it does not like to compress the liquid... (and it will push the oil out of the compressor.) See this on dual air setups.. or cases where the clutch stays locked up...
Good Luck,
Bryan

 

the a/c should run only in a/c or in defrost, and if its staying on with the key off its hanging. or the ignition switch is still energizing the relay. with it off the only thing should have power is a clock or gauges, but most of these are minimal draws, shouldnt pull it down in a month.