I have a 99 Sebring JXi convertible, and the rear defrosters do not work. When I push the button the light comes on. I checked the two wires attached to the defroster grid and they are both solidly attached to the window. I have no blown fuses that I can tell when using a fuse testor. Any ideas what may cause this, and how do I trouble shoot it from this point? Thanks

 

Since the light is coming on, that means that the relay is working. (There's a relay in the fuse panel at the end of the dash.) With the system turned on, check for voltage across the grid. There should be a voltage drop across the grid of between 10 and 14 volts. Positive should be on the driver's side, ground on the passenger side.
If you have no voltage dropback there, check for a break in the wires leading to the grid.If you have voltage on the drivers side to a good ground, then the problem will be a bad ground on the passenger side. If no voltage to ground on the drivers side, then check for a bad circuit on that side.
I hope that's not too confusing.

 

It's a good bet that the terminal where the grid plugs in has broken off. It happened on my wife's "06. They can be soldered back on. It apparently happens a lot.

 

Well an update. I have not had the time to check out the voltage as dcotter suggested. I got back from a trip today and the side mirrors were iced over. After pushing on the defroster button the mirrors quickly melted off the ice. I will check the voltage across the grid to see what is going on. Like I said in my first post the two terminals are securely attached to the grid. It seems that the mirrors are tied into the defogger system, and they do work. Hopefully I have time over the next few days to look into it further. Thanks for the replies.

 

Update: I installed a new radio as the factory radio was intermittent. Whoever last worked on the radio installed a Jensen FM modulator and 10 disc CD changer. They cut some insulation off of the original ground, wrapped the ground from the modulator around the cut area, and then put electrical tape over it. Well that was the short preventing the rear defroster from working. I cut away the affected ground and put in a new butt terminal on the new radio ground. The radio works fine now, as do the defroster. I'm glad that I had not had a chance to check the voltage as I would never have found the problem, since it was associated with a completely different ground. Thanks for the replies from everyone. Now to find a cheap new right hand headlight assembly to install and the car will be perfect!