Short at Dimmer Switch resulting in No Dashlights

[cpm65]

I am about to purchase a 1993 5.0 Mustang GT Convertible. Right now it has a problem with the Dash lights going out. The previous owner (girlfriend's dad) traced it to the Dimmer Switch and he's replaced the Dimmer Switch fuse 3 times already. Every time we go to test the dimmer switch, it shorts out and kills the dashboard lights. Any help or suggestions would be appreciated.

 

[General karthief]

Has he replaced the dimmer switch?

 

[jrichker]

What does the car have for add-on equipment that uses the dimmer - gauges, radio, non-factory courtesy lights, etc?

 

[cpm65]

Correction: I got some more information. Three brand new dimmer switches have been installed and all result in shorts. However, this started after a mechanic replaced the heater coil, so we're thinking that something got knocked loose or was put back incorrectly. We're looking into it.