half a$$ing heater

[phatyaspen]

so i think some of my vacume lines came undone because my heater works when on the "full blast" position but no other :? whats going on with my tj lol im glad i still have some sort of heat though would just like to get low and medium blast back thanks

 

[TwistedCU]

If you are referring to the fan switch, it's probably the switch (I say this because the if the fan will run on high, it should work at a slower speed, too).

If it won't select between defrost and heat for example, i would say check vacuum lines.

 

[xxjas12xx]

im not trying to hijack this thread but im having a similiar problem, i noticed this morning that my heater only blows thru the defrost vents, any thoughts of why this might be????

 

[Snitty]

my heat is always either full or off... just the way i am.. all or nothing.. so that wouldn't really bother me

 

[phatyaspen]

snitty like i said im glad i got heat and all its just it kinda gets under my skin a lil...but you know heat is heat, the way i look at it the faster the heat blows the quicker it gets warmer

 

[jay79cj7]

Same thing happened to me in my 2000 XJ about a month or two ago. Full blast, nothing else. Its your resistor block. At full blast, your blower motor sees 12V. To make it blow slower, the switch adds a resistor or two in series with the motor so it sees less voltage. One of these goes bad and next thing you know you have an open circuit, except when you bypass the resistors because you are on full speed.

To fix it you have to buy a dealer part for about 25 bucks and find it under the dash. Its not by the switch, its in the ductwork. XJs and TJs of the same year have pretty similar interiors, so I assume yours will be behind/below the glovebox where mine was. Its rectangular in shape I believe, with 2 screws holding it in. The hard part was finding it. It was really easy from there.

 

[XJNick]

Hi,

phatyaspen,
Jay79cj7 is exactly correct, you have a bad fan resistor block.


xxjas12xx,

Your problem is most likely a broken or loose vacuum line somewhere in the climate control system. The dampers in the duct work are controlled by vacuum motors. If they loose vacuum, each motor will reset to a default position. The damper motor that controls whether air goes through the defrost, or dash vents resets to "defrost" by default. Restoring vacuum to the vacuum motor should solve your problem. Otherwise you may have a bad vacuum check valve, or bad vacuum motor.

-Nick :!: