This is pretty odd one for me.... let me start by saying my Battery is new.. my Battery cables are clean All the connections are good... I turned on my Rear Defroster on the other day and when I was sitting at a light the voltage guage went almost all the way into the red.. the dash lights got dim.... I Turned the rear defroster off and it went back to normal... I turned the Heater on full blast.. and it did not do this... I turned on everything but the rear defroster and the voltage gauge did not move.... any idea What could be going on... and my Battery is Charging at 14 volts... I didn't check it with the Rear defroster on..

 

It sounds to me like you might have a bad connection in the rear defrost circuit. Something there is causing a heavy current draw. Maybe try following the wiring and testing with an ohmeter until you find the part with high resistance.

 

which side does that wire run down... i am going to have to find a wiring diagram for this wiring...
also I would like to add it only happens in Drive if that makes a difference... Found that out dismorning...

 

anyone else?

 

Only happens in Drive?? That's really strange! I would pull off the plastic lift gate panel and disconnect the defroster then try it. I'll bet you have some messed up wires somewhere.

 

i was gonna say... if really sounds like there is a point in the wiring or circuitry that is shorting. i think that the wires run to the pass. side but its so easy to pop that rear panel off that it shouldn't matter the side, the whole thing an just come down. and as for the rest of the paneling that you might need to remove to trace the wire are pretty straightforward as well. if you break a couple of clips, then the JY is always an option. either way, look for other wires that might be in bad shape as well. i know you said this is the only issue, but take your time and give the wires a good once over.