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AC / Heater Blower Fan only works on one speed.

F

FormulaW66

New member
AC / Heater Blower Fan only works on one speed. Not sure the type of unit i have but its got dual zone controls. The fan can be set to off and 1-5 setings. The fan only turns on at setting number five. So its either full blast or off. As it was dieing settings 1 and 2 didnt work, then 3 went out then 4. Its starting to get hot in florida so need to fix this before 5 goes out.

Any Ideas what it is??? thanks in advance.
 


more than likely its the blower motor resistor, that controls speeds 1-4 at 5 its bypassed to a fuse. its directly behind the blower itself.
 
no its not part of the blower. it just happens to be right next to it squeezed up against the firewall. as long as you dont have the automatic temperature control the resistor is like 30 bucks at autozone.
 
pacothetaco said:
no its not part of the blower. it just happens to be right next to it squeezed up against the firewall. as long as you dont have the automatic temperature control the resistor is like 30 bucks at autozone.
Click to expand...


Not sure if i have auto temp. If it is what i think it is i dont think i do, its all manual controls (knobs and levers).

Thanks!!!:)
 
Regardless of manual or auto temp, they both have resistors. The speed control is little more than a 12V source with four speeds. 12V/full current is full speed, and then three progressively higher resistance circuits @ lower current resulting in slower fan speeds.

You can tell you have a bad resistor when only the high speed works as this is the only circuit unaffected by its presence.

The resistors are kind of a wear item as they're basically electrical ballasts - they take current meant for the blower motor and bleed it off as heat. These heat cycles will eventually kill the resistor and open its circuit.
 


Mine does the same thing except my DRLs turn off when I attempt to turn on the AC blower haha I'm hoping this repair will fix this issue aswell
 
did you put the resistor in and did it take care of your drl's problem..
I replaced mine about 3 weeks ago it worked great but now its back to oinly high speed anyone have any other ideas
 
If you are having that issue in combination with the issue with the drl's, it is likely the ignition switch.
 


pacothetaco said:
more than likely its the blower motor resistor, that controls speeds 1-4 at 5 its bypassed to a fuse. its directly behind the blower itself.
Click to expand...

This fixed it!!! Thanks Paco

What a pain to reach. If anyone else has to do this I recomend taking out the glove box and blower fan to reach it better. 3 screws on the blower and about 5-6 on the glove box and out they come right out . When removing the resistor all you have to do is take out the front screw and then slide it out because no way can you reach the back screws. Took me 10 minutes to figure that out.
 
could either be resistor pack or the fan ignition switch, mine did the same thing and it was the ignition switch.
 
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