taz888

Good day all.I own a 00 cherokee and having problem with heater switch no matter where i put switch it doesn't change location (vent,floor etc) it blows through defrost vent,i know my resistor is bad because only blows on hi,would this also cause this other issue need some advice,i made sure everthing is connected and not pinched before i asked for help.Thanks

reddragon72

You have a vacuum leak or clogged vacuum line. There is a diagram under the hood to show you the vacuum line if I remember right. But it all starts at the intake manifold with a one way valve that looks like a UFO(it just does) and then a rubber elbow with plastic tubing. This also runs your cruse control so that will not work either. The quickest way to find the leak is to blow into the tub from the manifold and see if it leaking, if not then ckeck the valve(UFO looking thing) on the manifold and see if it is working. You should be able to blow one way and not the other, oh and mark this is up so you don't install it backwards. And while you have that off stick a toothpick into the hole in the intake manifold to make sure it is not clogged either(NOTE: do NOT drop the toothpick into the hole!!!!! tap one end if you have to to make sure you do not drop it in there!) good luck finding your leak, it can be a pain.

1987 new toy

there are vacum lines that run off the manifold to the heater control then all the way along the passenger side fender under the battery to a canister front pass corner of the bumper with plastic line those line under the battery to the canister and back get extermily brittle and have most likely broke. That5 canister holds a reserve of vacume so when you accelorate and the engine needs the vacume it does not take the vacum from the vent control and the cruise check those lines.

taz888

I want to just say Thanks i must of knocked off hose to canister. Taz888

1987 new toy

your welcome, so that was the problem uh