Battery cut off switch
The relays are to kill all the power to the front.
The NHRA only cares that the master switch kills the engine/fuel pumps.
If you've never had a car or seen a car burn to the ground because of that always hot alt wire, then you may not get why some of us use an extra relay. On my cars, you throw the master, NOTHING and I mean NOTHING is hot outside a 2' cube in the trunk PERIOD!
Crude diagram with a S605 relay in the alt charge line but kills the system flat!
If you have a street car, the switched/activation lead wire for the S605 needs to come from a keyed source, otherwise, when the master switch is on, there is a constant draw on your battery the way the diagram shows. Not hard to accomplish.
I also don't like a 0 gauge or larger wire being hot all the time either, thus the ford relay. Yeah it takes a bit more wire, rather have a smaller gauge wire short than a 0 gauge or larger.
There's a minimum acceptable NHRA standard and there are improvements, I prefer the latter.
The relays are to kill all the power to the front.
The NHRA only cares that the master switch kills the engine/fuel pumps.
If you've never had a car or seen a car burn to the ground because of that always hot alt wire, then you may not get why some of us use an extra relay. On my cars, you throw the master, NOTHING and I mean NOTHING is hot outside a 2' cube in the trunk PERIOD!
Crude diagram with a S605 relay in the alt charge line but kills the system flat!
If you have a street car, the switched/activation lead wire for the S605 needs to come from a keyed source, otherwise, when the master switch is on, there is a constant draw on your battery the way the diagram shows. Not hard to accomplish.
I also don't like a 0 gauge or larger wire being hot all the time either, thus the ford relay. Yeah it takes a bit more wire, rather have a smaller gauge wire short than a 0 gauge or larger.
There's a minimum acceptable NHRA standard and there are improvements, I prefer the latter.