Re: kill switches
Under the passenger dash worked for me, as the positive cable from the battery stretches around to that area in the engine bay in order to connect with the starter. My switch is like a 90 amp epoxy cased unit from JC Whitney. I enlarged a carpet fastener hole (kinda rusty by now) on the firewall to 5/8 or 3/4 inches. The connector end of the switch is of course in the engine bay. The keyway of the switch is pushed through the hole in the firewall and held tight by the switch nut, so the switch is in the cab. If you're really trying to conceal it, you can probably get the switch installed fairly high on the firewall in the cab and behind the heater duct under the dash. Mine is not so high, but its not really in plain view for anybody looking in. Just FYI if needed, install the switch, attach the lead battery cable to the positive on the switch, and run a new 2 foot piece of 4 - 6 gauge battery cable from the negative on the switch to the starter. I have a battery isolater and another battery too, and it all has worked really well for me. I looked at getting the switch in under the drivers side, but there just didnt seem to be enough room and I would have had to string too much cable. DRAWBACK: the switch is not really reachable from the drivers seat. Good luck, hope this helps.