rear defroster help

[SWOOOSH]

i have replaced the switch with a good one and now i can get the light to pop on for a second but thats it. does anyone no if there is a relay and where it is. for some reason when i get it to try to work it puts a big load on the system and the lights will go dim. any other ideas would be great full.

 

[salvageV6]

It could be the purple wire back at the window itself.

Drivers upper corner of the window, goes through the headliner back to the switch.

Sometimes it breaks off and shorts out.