rear defroster is not working

I have a 2002 Mitsubishi Galant and my rear defroster is not working. Here is what I have done to try and resolve the issue: checked fuses... None blown, even replaced them replaced the defroster relay I even went as far as replacing the HVAC controls. I checked the contacts at the rear defroster and when the deflated is turned on, the line receive 13.86 volts. When the defroster is turned off it drops down to around 5volts. I thought it might be the rear window with a crack in the line but it's not because i have anoter galant in the glfanily and I ran a line from the defroster power like that connect to the window an ran it to the window that is not working. Turned on that galants and turned the defroster on and my window heated up in seconds. So i know it's not the window. I checked where the relay is plugged in and 2 pins on the relay get the same 13.86 v and the other 2 seemed to have only 0v. I'm not sure what the 0v are but I'm assuming it's the ground. What else can I possibly Check to resolve this. I am completely stumped... It seems that everything is working because the window is receiving the power. Also, on the other galant, it's a '99, the window voltage is 14.4, would the .6v really matter?

When you checked the voltage getting to the window, was the plug connected to the window?  Or did you unplug it from the window to check it?   If it was not connected to the window, there was no load on the wiring, if there is a bad connection somewhere, without the window plugged in there will be no current draw on the circuit.  No current draw = no voltage drop.

WHen I checked the voltage, I unplugged the wire. BUT I also connected the plug and checked the defroster like and it had the same voltage - 13.8v

When you checked for voltage at the rear window, did you check it across the defroster grid or to ground?

hey you are not stupid you just lost the ground to your relay.ground pin 85 or 86 to body ground or battery ground when you turn it on it will workboxead78