Ok So i did read the previous defroster comment on the v6 info and it said a relay switch for the defroster relay, mines doing the exact same thing, but when i run the defroster at night my lights go dim my batter goes into the red and i dont dare crank the stereo, plus if i press it a second time it just makes a clicking sound and turns back off right away doesnt even do 2 minutes, so it could be the defroster relay but something leads me to believe it has to do with the battery being so low that it shuts off whtas not necessary, or it could just be the relay...If it is the relay is it just the button that needs to be replaced it also makes a weird sound when i run heat or defrost and lets out a slight hint of Marijuana which i wouldnt doubt if it was smoked in the car before considering the people i bought it from were in there 50s and total pot heads and i found a joint in the car when i bought it which went out the window... so i would like to pull the dash do some cleaning and see if i need to replace the part that makes the strange sound when i use heat or air, while at the same time replace that defrost button... Iam not quite interested in tackling the dash on this thing because its gigantic, comparing it to my 77 camaros dash.... is it possible that all it is dirty or will i really need to replace stuff for that heater to run quietly and efficiently ? it heats up the car but it makes a REAL racket!!!

 

50 year old stoners...nice

no clue about the problem...Z28pete will prob know something...

 

Yah its real great ... Not! they never changed anything on it and the person that lived next to them i work with told me that they were always doing weird **** in there house and outside and always messing around but Here in North Dakota the weather isnt always that great... so i would like rear defrost and heat without killin the battery so help is a good thing!

 

Three possibilities come to mind. One possibility is that there is a short in the defroster circuit, but that should blow a fuse or trip a breaker, unless the fuse was bypassed.The other possibility is that you have a weak alternator or too big of an electrical load. The defroster puts a heavy load on the alternator, and if you have a lot of other stuff running at the same time, a weak alternator will let the voltage drop. The other could be a sick also battery, but then you should have problems starting. As a starting point have the alternator and battery load tested.