alright soooooooo figure this one out for me guys.


if i put the vent **** on my face and and then put it on ac or max ac it works accordingly.

if i put it on ac or max ac right away it blows up to the defrost

also any other vent **** setting with send it to defrost.

i already checked for vacuum leaks and rerouted the vacuum lines by the pump and 4wd actuator and eliminated the 4wd solenoid so all we have left is the vacuum pump and vacuum reservoir(that big box thing between the battery and pump.

what could it be?

 

1. Pull the hose connecting the vacuum pump to the accumulator with KOEO. Does it start to run? If yes, go to 2, if yes and 4 if no.

2. Does it stay running for a bit then shut off? If yes, Go to 3. If no, go to 4.

3. Cycle the key off then on, does the vacuum pump run? If no, go to 4. If yes, Go to 5.

4. With KOEO, disconnect the wire harness from the pump and plug it back in.
Does it run then shut off again? If yes, you have a bad vacuum pump and have a leak in the system causing the pump to overheat. The damage has already been done, so just buy a dorman replacement for $50. Repair leaks.

5. You have a vacuum leak. Your pump may or may not be damaged from overheating and I would recommend replacing it once you figure out what is leaking.

Common vacuum leak places are the 4-way plug slipping off behind the glove box, The hose deteriorating between the pump and the reservoir (accumulator), the hoses near the knuckles and the hub seals themselves.