Hi , Had the air on today and I can't get hi speed. I get the first three but not hi. What do you guy's think it is ? I have front and rear air, the rear works fine. Truck is a 2002 SLT + 5.9 4x4. Thanks...

 

Check the resistor located under the dash / glove box area. Typically when they fail the blower will only work on high speed, but that's the number one place to start troubleshooting. If you have a hard time removing the connector from it look closely at the contacts and see if they're melted / corroded. If so, splice the harness with a replacement connector from the dealer.

Bob

 

+1 Bob

 

+2 on the resistor/harness

 

Thanks Guy's...!

 

+3 resistor/harness. Resistor about a $15 part at dealer.... Harness thats another story once you splice them together they should be fine.

 

Any place online I can buy the Resistor/Connector Harness from ?
Thanks..

 

I think only a dealer item for the harness, resistors yes.

 

Ok, Thanks again...

 

I just replaced my resistor in the winter. I only had the two highest speeds since I had bought the truck in '06. It completely failed in the winter. Once I replaced it, I have all my speeds back. It was $15 from AutoZone.

I would spend the $15 on the resistor before jumping on the harness.