Have a 93 Pontiac Grand Prix the heater just stopped working. Worked fine yesterday and even earlier today. The heater won't turn up. It says its on but no air coming out to defrost. What could that be ? Check fuses and still nothing

SOURCE: Heater blower won't cut off, even with ignition turned off

try looking at your x relief relay it may be sticking

SOURCE: 2005 Pontiac Gran Prix blower

Check the blower motor which is behind the right side of the dash, in the lower right side of the HVAC Assembly, above foot area of the passenger floor. The other thing to test is the blower motor resistor which should be next to the blower motor.

SOURCE: Rear Defroster Problem

1 st of all check all the fuses if all are good it may be the switch itself .......if you are referring to just the defroster ensure both connections are connected to th rear window if there are any breaks in the defroster lines as you will they sell a metal fill type repair kit not expensive and with the use of tape and this mixture you can easily repair the breaks in the defroster lines ........but first ck your fuses and connections maby determine with the use of a test light and check for power at both the switch and the rear wire connections for power to them otherwise it is most likely the switch

Testimonial: "Thank you. There's power at the fuse and power up to the switch is good. No power at the rear tab or grid so I guess I need a new switch."

SOURCE: 2005 Grand Prix heater works fine when blower is

Sounds like a clogged heater core- insufficient coolant circulating through heater core, and as soon as you blow air past the core, it get cooled off.

SOURCE: 2004 Pontiac Grand Prix GTP front pass turn signal doesn't work

you would need to buy a blinker relay