2001 Sonoma Blower Switch

[duggerns]

Hi - new to the forum - I have a 2001 Sonoma with A/C and the blower switch operates on speeds 3 and 4 but not 1 and 2. All other heater and A/C functions work fine. I did a search and the blower resistor seems to be the most likely cause, but when I removed the resistor ( coil wire type) it had no obvious defects - everything was clean and sound, including the wire connections. I also checked the fuses and they are okay.

Can the resistor be the problem even if it looks fine? If it's not the resistor, is there a relay that might cause this or could the switch be the problem?

Thanks for any help .. Doug

[bill190]

Well anything can be the problem. The resistor is the most common problem.

 

Test the resistor connections with a multimeter on the ohms scale.

 

If there are 4 connections on the resistor (connector unplugged), you should get a reading between any two connections. And probably around 3 ohms between the two furthest apart connections.

 

How to use a multimeter...

http://www.google.com/search?hl=en&saf...ter&aqi=g10

[bowtieboy89]

im not sure if its set up the same but at school we had a 07 2500hd come in for injection pump work and in our spare time we checked out that exact same problem all the connections were clean but a couple of the female side of the spades were loose we squeezed them down and that fixed it

[duggerns]

Guys - thanks for the advice - I did a resistance check and a continuity check and found that two of the small resistors within the "resistor" were not working, even though they looked good and then, just for confirmation, put in some jumpers and the two low speeds worked again - got a new resistor ( dealer) for $20 and things work fine.

Thanks again .. Doug