When i turn my heater on (blower) my car tries to stall out. What can cause that to happen?

engine stalls when parked? or driving fast>? not told. engine stall is 0 RPM engine as in dead.
and restarts easy.
does engine STALL going from park to DRIVE or REVERSE.
that is a super rare even so rare I think it is just coincidence.
the cars cab heater, blower fan turned on low to high? at the dash knob HVAC.
or at engine fans, Radiator rear or font, fan, condenser HVAC.

first off the blower fan is fused, say about 20amps, and is never going to overload the battery or 100amp alternator ever, not possible. nor the GOOD engine,
wiring hacked yes. my answers or for NOt HACKED CARS OEM STOCK.

answer 2;
engine is very sick and weak, and RPM is too low say 600 not 800 or more.
so any load on the engine stall is it, blower or going in to drive.
in drive, foot on brake RPM is 800 hot or 1500 cold. not 500 ever.
those need to be known first.
or get the car services for SURE if you can demonstrate he failures. to them.
this answer if for any engine on the hair line cusp of stalling before it does stall.

see?

Try turning on headlamps an radio instead of heater blower to see if same thing happens . Also check G105 engine ground for being lose or corroded .

check idle speed control motor .idle air control

almost sounds like the battery or alternator is bad.

Only get a vacuum leak, if the booster check valve
failed & may effect the idle,not sure if it would be enough
to stall out the motor
What is the emergency switch? Parking Brake warning light?
That wouldn't have any effect on the engine idle

The stalling is most likely caused by the Idle Air Control solenoid (IAC) and/or a dirty throttle body . This can also cause erratic acceleration if your throttle is sticking.

The problem with your blower motor is most likely caused by the blower motor resistor. All of the speeds except HIGH are routed through it. It is also possible (but not real likely) that your blower control switch could be bad.

if this happens while the defrost of ac is turned on, it could be a seized ac compressor which will cause the serpentine belt to squeal and drag making the engine sometimes stall. if it happens with the ac off and the selector on say the floor, or dash vents, the issue could be a bad alternator and battery. this is confirmed when the blower motor engages and the lights dim and then the truck goes dead.

I had the same problem. you have to either keep replacing the filter until the line has cleaned out or blow the filter out with an air hose. Tedious but cheap.

My 94 Sedan DeVille had the same problem. The car ran great but would stall whenever I stopped at a stop sign or traffic light. Turned out to the the TPS (Throttle Position Sensor). It monitors and controls the idle. What happens is the secondary idle (idle when the car is warm) is too low. Since all the controls for fuel mixture, idle etc are done electronically, they can't be manually adjusted. The TPS is the most likely cause of your issue. A diagnostic test (performed free at most chain auto parts stores) will be able to confirm this or lead you to another component. Best of luck to you!
Greg

Often when the battery is disconnected or replaced the computer will lose it's learned idle settings. You could try letting the engine idle in park until the engine temperature comes up to normal and leave it like that for a few minutes, then put the Air con on and let it idle again for a few minutes, then switch the air con off and put it into drive. If it does not stall, let it idle in drive for 2 minutes or so, and then do the same with the Air con on. This should relearn the base idle settings and stop it from stalling on you. Before you carry out this procedure you should make sure that when you replaced the battery you didn't remove any other plugs or knocked anything that may be causing the fault. If you try this procedure and it still stall when you select drive, you will need to get a Mechanic to check the vehicle over.

Hope this helps,
Mark.