Re: h/u remote turn on wire?
The famous Bosch relay that people use draws 160 milliamps of coil current.
Modern amps use very little current on the remote. Typically they're only 10 milliamps, which is 16 times less than a single relay. I would tie the remotes together and measure the current that they draw from 12V when combined. If it's less than 100 ma I'd skip the relay.
Old school amps drew a lot more remote current than modern amps do. The rules have changed.
1999 Buick Park Ave Ultra
Head Unit: JVC KWHDR720
EQ: Audiocontrol EQL
Front Stage: Hybrid Audio Technologies Imagine 5.25 mids, Morel Maximo tweets
Sub Stage: Boston G3 10", 0.5 cu ft sealed
Amp: PPI Phantom 900.4
Rear Fill: Boston SE953 6X9's