i have a 2002 gmc sierra and am having problems with my heater speeds

speed 1 doesnt work at all but the light comes on

speed 2-4 work

speed 5 doesnt seem to blow as hard as it should speed 5 feels like speed 3 or 4

any ideas what the problem would be maybe the switch or the heater motor?

under the dash on passenger side is the blower motor resistor....pretty close to the blower motor itself. is a 2 wire connector going from resistor to motor.
don't pull that plug, but pull the plug on the resistor itself(5 wires or so if i remember right). if ANY of the terminals/plastic on the connector is melted, replace the connector. remove the resistor and check for same melting on pins/plastic. if melted in any way, replace it too. common problem on GM trucks....some cars too

The good news is that the resistor pack is under $25.00 and except for it being hard to get to all the screws to lower the heating ductwork it's a pretty easy job.

Actually The resistor pack in my 2004 was $55.00 @ dealer

It's an easy fix... and don't forget to change your cabin filters while you're in there.:icon16:

Since this post is a couple years old it's probably been fixed... :-)