The vents in my jeep seem to randomly work and almost always turns on or off when the jeep shakes enough (off roading). If there is a thread on this already please let me know. What would cause this? My guess is something must be loose, but I can't find anything obvious on this.
Air through vents works sometimes
- Thread starter QRFguns
- Start date
I would do a thorough inspection of the engine compartment vacuum tubing looking for cracks and checking how snug the rubber fittings slip onto the metal nipples.
Drive the vehicle with the blower on high, accelerate wide open throttle going up a hill if possible put your hand up by the windshield to see if the air is being diverted to defrost if it is you have a vacuum leak ( this is a safety default so if it fails you still have defrost) 99.9% of the time the leak is in the engine compartment. Check the plastic line from the engine to the right side where it goes into the firewall it will develop cracks and leak. There is 1 or 2 vacuum check valves in the system that you should be able to blow through one way and not the other, the line will have a tee in it and a hose the runs down to a vacuum reservoir under the battery tray. Make sure the hose is connected and the reservoir is not cracked. The plastic line can be replaced or fix the cracked section by sliding a piece of 3/32” vacuum hose over the cracked portion.