hckrach

I have a 2000 Cherokee Sport. I have a rather odd issue. My heat will only come out of the defroster. On the middle **** which controls off/ac/floor/vent/defrost/etc. no matter what setting it's on, the heat comes out of the defroster. When it is turned off, it is off, when I put it on ac/max ac/vent/floor/mix/defrost, the heat only comes out of the defroster. The temperature is not an issue, it is very warm coming out. I figured the something in the selector **** must be broken, so I went to Napa first, they said they didn't carry it, so I went to the dealer. The parts guy seemed to think it is a relay or resister, or even one of the blower motor attached to a door changing direction of the flow. He gave me a print out of the location of different parts under the dash, and said I could investigate it more with that info. My gut still tells me it is the selector ****/switch but only because it used to be fairly tight, and now seems loose. I do not have much to go on here. Any help would be greatly appeciated!

freegdr

are the vents cable or vacuum operated

Irongrave

sound like the Blower motor resistor.

hckrach

I doubt it is the blower motor resister because the fan switch works and I change the speed from low to high. Also I don't know if it's vacuum or a cable system

TTMK5

my fiance just got hers fixed, exact same issue , air only came from defrost no matter what setting . and hers was the vaccuum hose

freegdr

you now where the blower motor is there are some plastic tubes there different colors one should go to the vacuum ball behind the front bumper follow it to there check for craks or broken line ,also check the vacuum line that go from the ball to motor wher it gets vacuum

81Z4ME

Our 2000 Cherokee was like that awhile back. Everything came out the defroster vents and the cruise control light came on but cruise control didn't work.

Found the vacuum tubing behind the battery UNDER the battery - pinched and leaking. Replaced that piece of tubing and now the selector will change from floor, to vent to defroster, etc. and the cruise control works again.

Look for a leaking vacuum tube. Vacuum is what diverts the "doors/valves" in the ductwork to divert air from one set of vents to another.

hckrach

OK, thanks for the replies. I'll be honest, the heat and AC on cars is not even close to a strong point of mine. Does anyone have, or know where I can find, a diagram or something with the vacuum lines? Also, is it generally obvious when I see one leaking?

Jim_K

x2

Jono

x3

Jono

I have the same thing just didn't have time last weekend to look at but I hope to do it this weekend

no rdplz

Bingo! Check the vacuum line that leads to the ball canister behind the passenger side of the front bumper for cracks/splits/breaks. That line gets VERY brittle and can break easily. I'd put money to that being your issue.

hckrach

ok, the issue is not under the hood. There is vacuum in the line from the vacuum under the bumper. I pulled the heating/ac line off, and put my finger to in, and it held my finger to the line. The colored lines stay under the dash. They lead from the selector switch to various places under the dash. I have not pulled the dash apart yet to see where they go. As I said before, the switch was always very tight, and now it is very loose, so my money is still on it being something in the switch. Any thoughts or other ideas?

NapaJohn

X8 on the vac lines. If its blowing the blower motor is fine. VAC LINES Check the one that runs under your battery, Its hidden and easily missed .

shadowlm15

What happened with mine was straight above the oil filter and started theres a really small grey vaccum line that runs from inside through the fire wall and into the main vaccum lines around the ouside of were the hood seals. And that was cracked so i slipped and bigger hose over all of it and rtv'ed it permantly