free

1999 OLDSMOBILE SILHOUETTE
6 CYL • FWD • AUTOMATIC
Avatar
MAXPAUL123
  • MEMBER
  • 5 POSTS
I have a 1999 oldsmoblie silhouette the front heater will not switch from cold to heat and it will not switch from defrost to front pannel it coming out from all the vents I change the control pannel still no change what controls both that might be bad
Dec 10, 2010 at 5:30 PM
Advertisement
Avatar
WRENCHTECH
  • CERTIFIED EXPERT
  • 20,761 POSTS
That's pretty odd and probably a coincidence. The mode controls are vacuum controls and the temperature is an electric actuator. The control head is what operates both of them but I suspect you have 2 separate problems. You need to verify vacuum supply from the engine to the control head and make sure the vacuum reading matches engine manifold vacuum.
Dec 10, 2010 at 6:06 PM