Battery Disconnect with relay up front
All you are doing is "cutting" where the ignition switch feeds out of the bulkhead. That switched "ignition run" normally comes from the switch, out of the bulkhead, and feeds the ignition and regulator on 69/ earlier cars
On 70/ later it branches off and feeds some other stuff, including the later alternator blue field wire, idle solenoid on 6 packs etc. All you are doing is cutting that feed and using the power coming from the key to activate a relay / solenoid. THAT activation line is wired in series with the two small wires coming up front from your disconnect so that when you pull the disconnect, the relay drops out and kills both the alternator and the ignition
You do understand? That simply cutting the battery will not kill the engine. The alternator, once activated will continue to charge and to operate the system. This in fact is "an old wives tale" which goes "If you disconnect the battery and the engine dies, the alternator is bad."
One of our members drew this up. The solenoid could also be a relay, a good heavy one, heavy enough to switch whatever underhood switched loads you have. If you don't run a pump, or use a dedicated pump relay, and same with fans, etc, a good quality "Bosch" relay is probably good enough
Step 6 is not really necessary.
Follow along...........
The "cut blue" coming out of the bulkhead is your old ignition feed coming FROM the ignition switch. You want this to turn on the relay / solenoid THROUGH the small terminals of the disconnect. So from the bulkhead, goes to the rear through your small conductors, through the small terminals of the switch, back up front on the second small conductor, and to one of the small terminals of the solenoid / relay. The second terminal goes to ground. YOU COULD run that second solenoid / relay terminal to ground through a second hidden switch for anti theft.
All you are doing is "cutting" where the ignition switch feeds out of the bulkhead. That switched "ignition run" normally comes from the switch, out of the bulkhead, and feeds the ignition and regulator on 69/ earlier cars
On 70/ later it branches off and feeds some other stuff, including the later alternator blue field wire, idle solenoid on 6 packs etc. All you are doing is cutting that feed and using the power coming from the key to activate a relay / solenoid. THAT activation line is wired in series with the two small wires coming up front from your disconnect so that when you pull the disconnect, the relay drops out and kills both the alternator and the ignition
You do understand? That simply cutting the battery will not kill the engine. The alternator, once activated will continue to charge and to operate the system. This in fact is "an old wives tale" which goes "If you disconnect the battery and the engine dies, the alternator is bad."
One of our members drew this up. The solenoid could also be a relay, a good heavy one, heavy enough to switch whatever underhood switched loads you have. If you don't run a pump, or use a dedicated pump relay, and same with fans, etc, a good quality "Bosch" relay is probably good enough
Step 6 is not really necessary.
Follow along...........
The "cut blue" coming out of the bulkhead is your old ignition feed coming FROM the ignition switch. You want this to turn on the relay / solenoid THROUGH the small terminals of the disconnect. So from the bulkhead, goes to the rear through your small conductors, through the small terminals of the switch, back up front on the second small conductor, and to one of the small terminals of the solenoid / relay. The second terminal goes to ground. YOU COULD run that second solenoid / relay terminal to ground through a second hidden switch for anti theft.