Does the blower motor resistor effect fanspeed 5 [Archive] - Forum


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01-17-2007, 06:03 PM
Does the blower motor resistor effect fan speed 5, I was under the impression that even with the blower motor resistor being completely failed that position 5 would blow. I'm inquiring for a friend that is now heatless, his dealership is telling him its the blower motor resistor, which I'm doubting, because it doesn't blow on any speed, and all speeds worked up until the failure. I just don't wanna put a blower motor resistor in for the kid if its a waste of time. I don't do those contortionist tricks unless I need to, I've done it on my GA before, and its basically something I try to avoid at all costs. So, does anybody know for a fact whether or not fan speed 5 can fail with a blower motor resistor. I tried to upload the picture in the hvac thread of the new resistor to try and determine the circuit, but this pc I'm on now won't load it. Thoughts?

01-17-2007, 06:47 PM
from my understanding, a bad blow motor resistor only eliminates 1 and 2 from the fan speeds while the others work fine

01-17-2007, 07:52 PM
well the resistor usually provides resist in speeds 1-4 and full voltage on 5, so no the resistor does not affect the blower that way, but if it is shorted then the speed on 5 will be slower.

if you arent getting a high speed, bypass the resistor and see if it works from there, or just apply power to the blower itself directly

since you said the blower doesnt go at all now, i would also check power and ground, make sure they are ok. other than that, prob a new resistor, the whole thing sounds shot if its that, but it could very well be a bad motor also

also if you need a pinout and wiring diagram, i got em if you need em

01-17-2007, 09:41 PM
Check the fuses. The blower motor resistor does not effect setting 5.

01-17-2007, 09:46 PM
yah srry, i didnt check the wiring diagrm, the resistor has no control over speed 5, here is the diagram, thanks spruce

01-17-2007, 10:28 PM
Well, I went to pull his blower motor resistor and start looking at things and I found one of the wires is pulled out of the connector, and I think more are loose, I was able to wiggle things around and get speed 5 blowing full on, I'm going to investigate more when its about 20degrees out. Appreicate the wiring diagram, that will help as there is some definte trouble shooting, and thats exactly what I was looking for.

06-30-2010, 12:18 PM
Thanks for the diagram. I am trying to ohm out the resistors for the fan speed control but I can't quite read the values on the diagram. When I blow it up it gets more fuzzy. Could you tell me what the values of the 4 resistors are?
Rusty Wood

06-30-2010, 12:49 PM
my blower resistor is bad in the 1&2 position haven't gotten around to replacing it

06-30-2010, 04:26 PM
Here is a larger diagram for you.