Is there any drawback to mounting the starter solenoid on the firewall on the inside of my car? would it be dangerous? seems I can hide most if not all of the wiring in the engine compartment if I just mount it inside the car.
Ok, so you have a hot lead running from trunk to fender now? I'd move the sol. to the trunk and run the extra wire with a relay so the battery wire is only hot on crank. You could also move the solenoid to the wheel well say the backside of the headlight bucket and not have to move as many wires if you're ok with the battery hot constant cable running the length of the car.
Jon
You can actually run 2 solenoids if you'd like, 1 standard power-energizing type to run the starting circuit and 1 grounding type to run the power feeds. You'll have 3 wires running up front - 1 heavy-gauge, maybe 1/0ga or 2/0ga to the starter and 1 medium gauge, maybe an 8ga to a standoff to join up with the feeds and alternator output and 1 circuit-breaker protected 14ga wire to your battery cut-off switch. The starting solenoid's "S" terminal would be energized by the ignition switches "S" post and the power feed solenoids "on" terminal energized by the battery cutoff switch which needs to be no more than a toggle switch (hidden if you want to use it as a form of anti-theft protection. Add a Ford-style EFI pendulum switch to that feed solenoid ground wire and you can add the protection of automatically cutting off power in case of an accident.