Manager Forum

Customer came in with blower issue,only working on high or not at all. Inspected fuses all good,checked switch to resistor for power at each setting ok. Found resistor melted and pigtail melted in resistor. Replaced resistor and wired in new connector. Still blower inop..Replaced fan switch and another resistor,fan inop. Unplug fan from resistor checked power output at blower plug,all settings are being read with volt meter at male connector end. But plug fan in nothing?????? Have tried 3 new blowers...

Check the voltages on both wires at the blower with it plugged in and turned on, sounds like you might have a ground issue on this.

Agree with ground issue. High blower by passes resistor and is triggered by direct switch (or relay). Check ground resistance at resistor. Even though the ground reads with test light an incorrect diagnosis may be had because of an incorrect load reading. There was an updated wiring process for my 01 Suburban to resolve this issue. A warning here, the updated harness defiantly changed the velocity of the blower a bit so if this is the issue warn the customer that the fix will cause changes.

Fixed problem,fixed problem.
Bad ignition switch.........