Re: Avital Phoenix 2 alarm
The mercury switch connects to the multiplexed trigger on the alarm and to ground. When the hood opens, the switch completes a circuit and the multiplexed trigger sees a ground, setting off the alarm. When the hood is closed, it's an open circuit. On any DEI alarm, I believe the multiplexed trigger is either the blue or blue with the white line.
94 Caprice Classic LS: DEH-P800PRS, TS-C720PRS, MRV-F545, MRD-M1005, 2 Fi X 12s in 2.5 net cubes sealed; 97 Grand Cherokee TSi: CDA-9855, TS-D1720C, active off HU power
Resident Jeep Expert, Mother Fucker