1999 GMC Sierra Heater temp control

1999 GMC SIERRA
182,000 MILES • V8 • 4WD • AUTOMATIC
Avatar
RSNIDE
  • MEMBER
  • 1 POST
Heater temp is hot while turned all the way up and goes cold when turned down even just one notch. At times, heater remains hot through all temp control settings
Jan 6, 2010 at 8:39 AM
Advertisement
Avatar
JACOBANDNICKOLAS
  • ✓Experienced Mechanic
  • 110,248 POSTS
Have you checked the blend door? It could be sticking.
Jan 15, 2010 at 5:19 AM
🔧 Tools & Auto Repair Parts
Find automotive tools, diagnostic equipment, and replacement parts for your next repair.
Shop on Amazon →
Paid affiliate link. As an Amazon Associate, we earn from qualifying purchases.
Add a reply
Join 2CarPros for free, one of the most advanced car repair communities on the internet. From first-time drivers to seasoned mechanics, everyone is welcome to reply, share details, and get better answers. You can add a temporary image or video first; uploads are limited to 20 MB.

Ask a new question

Frequently Asked Problems for This Vehicle