Classic GMT800/GMT900 summer problem: fan speeds 1–4 dead, only high works. That’s the blower resistor — high bypasses it, which is why it survives.
But here’s the part worth discussing: a lot of us have replaced that resistor more than once. The repeat offenders are almost always a melted connector pigtail making bad contact, or an aging blower motor pulling too much current and cooking every new resistor you feed it.
Full diagnosis + fix write-up (including the amp-draw check): Silverado Blower Motor Only Works on High
Show us what you found:
- How many resistors have you been through, and did the pigtail look melted?
- Anyone actually clamp-meter their blower motor before/after? What did it draw?
- Did replacing the motor along with the resistor finally end it?
Post the crustiest burnt resistor and connector photos you’ve got — best worst-case wins bragging rights.