Here is the elec line lock setup I have, a solenoid on each rear line controlled by a switch to each solenoid. I mounted the switchs to the rear axle Tcase shifter to be able to disengage the rear axle and lock a soleniod in the same movement. (you can only stop for 4 seconds in a comp). The longer the solenoid is engade, the hotter it gets,,,,,,the hotter it gets, the more amps it draws to be able to stay locked. Not a good setup for an E brake but OK for 10 minutes or so.