My 1994 Chevy Suburban heater only works on the top 2 speeds and does nothin on the slower speeds. Any ideas?
Stinky
Stinky
Heater motor only works on 2 highest speeds.
- Thread starter Stinky Peterson
- Start date
- Status
- Joined
- Sep 28, 2002
- Messages
- 39,798
Usually this means that the resister pack/module is shot. It usually just leaves the high speed when it takes a hike on you. In TJ's it's a simple fix. Remove a little plastic vent panel and you unplug it ...etc...
Start from the squirrel cage and work backwards (or from the switch and work forward) and you'll probably see a seperate little "board".
Before you replace it, do a continuity check just in case it's the switch (less likely).
Good luck!
Start from the squirrel cage and work backwards (or from the switch and work forward) and you'll probably see a seperate little "board".
Before you replace it, do a continuity check just in case it's the switch (less likely).
Good luck!
If your vehicle doesn't have an electronic climate control system (push buttons, auto temperature, etc.), it's probably one or two blown power resistors. Here's how this design works:
You have a 4 position switch at the console for fan speed--low, medium-1, medium-2, high--and a series of resistors--R1, R2, and R3.
In the low position, current goes through R1, R2, R3 in series to the blower motor. In the medium-1 position, current goes through just R2 and R3. In medium-2, current goes through just R3. Finally, in high, it's full voltage to the blower motor via the blower relay.
It sounds like you've blown R1 and/or R2 (if you have the regular climate control) which means you have to replace the resistor assembly.
However, if you've an electronic climate control system, it probably means you'll need to replace what's called the "Blower Control Module"--which is basically a solid state power transistor pack.
Either the resistor pack or the blower control module is typically inside the passenger compartment--usually near the front of the dash near the blower motor or evaporator housing.
You have a 4 position switch at the console for fan speed--low, medium-1, medium-2, high--and a series of resistors--R1, R2, and R3.
In the low position, current goes through R1, R2, R3 in series to the blower motor. In the medium-1 position, current goes through just R2 and R3. In medium-2, current goes through just R3. Finally, in high, it's full voltage to the blower motor via the blower relay.
It sounds like you've blown R1 and/or R2 (if you have the regular climate control) which means you have to replace the resistor assembly.
However, if you've an electronic climate control system, it probably means you'll need to replace what's called the "Blower Control Module"--which is basically a solid state power transistor pack.
Either the resistor pack or the blower control module is typically inside the passenger compartment--usually near the front of the dash near the blower motor or evaporator housing.
Unfortunately, may also be expensive to replace in the $150-4000 arena if done by a dealer and if the resister pack is a prt of the motor itself
Patman
Staff member
Same thing happened to me on the 97 GTP I used to own. It started out where the lowest fan setting wouldn't work, only 2-3-4 would work. Then only 3-4 would work, then eventually only 4.
It was the blower fan resistor module. Didn't cost much but was a pain to replace! It was tucked under the dash pretty good. Took me at least an hour to do it.
It was the blower fan resistor module. Didn't cost much but was a pain to replace! It was tucked under the dash pretty good. Took me at least an hour to do it.
Thanks fellas, now all I have to do is find it!
Get a Haynes manual for $15.00 or so, if you don't have a Factory service Manual. It will help you locate the resistor panel. If it is like my 94 Impala, it is under the passenger side dash, behind the kick panel,and next to the haater blower. It does not require you remove the blower to get to this resistor panel so it is fairly easy.
The same thing happened in a Honda Civic that we use to have, and it was blown power resisters in the switch. I used a couple of large Radio Shack ceramic power resisters wired in parallel to fix it, and had no further problems with it.
Thanks everyone, it was the resistor.
- Status
Similar threads
