Trying to bypass the ebrake on an app radio heard you can use a relay but not sure anyone done this before? I have an 02 blazer

 

I've always just grounded the e-brake sensing wire. On those DVD and NAV units that have that sensing wire it's supposed to be a safety device to prevent people from watching movies and other things while driving. The switch on the e-brake simply goes to ground when the e-brake is engaged, so all you have to do is ground that sensing wire with your HU ground and voila, that stuff works.

 

I've just taken that e brake ground wire and hooked it to the ground wire on the head unit.

 

you don't take the actual ebrake ground wire out. YOu just ground the wire from the radio that's suppose to go to the ebrake and ground it to a piece of metal