My heat doesnt work why ???

Is it just the AC or does the heater and vent also only blow on 1 and 4? If it does happen in all modes then the blower resistor pack is more than likely bad.

there is a blower relay circuit board located right by the blower motor which sounds like your problem to me i've worked on several that had the same type problem and thats what it was. the two blower motor wires will plug into it and there are two screws that hold it on

to me it sounds like a loose wire may be exposed to metal touching that one point or another and it's definitely an intermittent problem and that's what it sounds like to me

It could be your fuse or relay or blower motor resistor

Hello Eric...

As you do not have heat, one or more heater & AC air delivery and/or temperature mode door actuator may have failed. This can result in incorrect air delivery or temperature. If this occurs, fault code(s) will be stored in the HVAC control module and should be recovered (A code reader is required) to assist with diagnoses.

we talk her about any fan ( blower ) or (condenser) fan .what you ( repaired twice ) .why you remove the dash .how many fan motor you have .
if you turn on the heat or ac the smoke start come from where . you say its fried (any part) .

It's the switch in the control panel. Would you like instructions for replacing it?

does your cruise control work??? I had no heat or a/c intermittent, and cruise did not work. I replaced the ignition switch (behind the key) and everything works fine now. Switch was 80 dollars and about 2.5 hours of work... the shop wanted 450 dollars.

2001 Elantra, heat only comes thru when driving, other than that its always cool....why doesnt the heat come thru when Im idling?

if your ac blows hard and cold then it could be your heater core, but most likely the thermostat is going bad. When those fail it leaves the radiator in an open position and all your coolant goes through your radiator, so when its cold out its hard to get warm air out of your heater. IF it were my jeep i would take it somewhere and have the radiator and heater core flushed and check the thermostat. IT can be done yourself but requires some flushing agent from auto zone or auto parts store and some time and auto knowledge.

Goodluck.