today i turned on my defrost and i looked down after 2 minutes and it wsa off. so i turned it back on and then it turned off immediately. i then pushed the button, and when i pushed it a wierd buzzing noise came from inside the dash on the passenger side. i waited, then tried it again...it turned on but only for a sec. it wont stay on, all it does is turn off by itself. do these switches turn off after a certain amount of time? or is sumthing broken?

 

I think they stay on for like 10 minutes. It sounds like it may not be grounded. Check the hatch struts and see if the wires are connected. Check to see if the ends of the struts are on properly. If they are I suppose it could be a faulty switch.

 

Don't have a rear defrost in mine, but aren't they operated from a timer relay? The buzzing sounds like a relay that won't stay engaged.

 

if it came from the passenger side then that means 1.its a firebird and 2. you need to replace your relay. mine did the same thing in my camaro i replaced the relay and it works fine now.

 

yeah the noise is most likely the relay...

 

can i get the relay from autozone or advanced auto? or only from GM? how much do they run?

 

yes, and about 15 bucks

 

i went to local autozone, oreillys, and advance auto, no body has it. is there any other place i can get one?

 

Most likely this is only a dealer item.