battery disconnect switch

[gmorrell]

Automotive primary wire, is usually designated GPT (general purpose thermoplastic) and is specificed to loosly conform to SAE J1128. There are a whole bunch of other designations within J1127 and J1128, mostly dealing with temperature and oil/fuel resistance.

Battery cable for automotive or marine use is often PVC (poly-vinyl chloride) insulation.

The small strand very flexible cable you're thinking of is more likely Neoprene jacketed welding cable.

Waytek Wire has a great selection of automotive wire and cable, and connectors of all sorts.
http://order.waytekwire.com/category2/M37/360/WIRE AND CABLE/

 

[MD Ever]

I could race with 3 dead hookers in the trunk and no one would know.

-Sam

That is sig quote material if I ever saw it.

 

[twr]

well i hope i dont need a metal box. the plastics are only $9
This just made me happy.
http://store.summitracing.com/partd...&N=700+4294925143+4294862977+115&autoview=sku

That box is not acceptable, I was almost asked to leave Bandimere with that one. Whatever box you get, it will need to be vented to the outside of the car. This is the one I got. I also got this switch and have everything wired legally. I mounted my switch behind the drivers tail light. When I get to the track I take the tail light out and I'm good to run. I thought of the fuel pump/ecm idea, but they will catch you if the check it correctly. I had to step on the brake and try to start the car to prove it was done correctly. I asked about wiring the clock and radio to keep power to them and they said that was okay.

 

[gmorrell]

That box is not acceptable, I was almost asked to leave Bandimere with that one. Whatever box you get, it will need to be vented to the outside of the car. This is the one I got. I also got this switch and have everything wired legally. I mounted my switch behind the drivers tail light. When I get to the track I take the tail light out and I'm good to run. I thought of the fuel pump/ecm idea, but they will catch you if the check it correctly. I had to step on the brake and try to start the car to prove it was done correctly. I asked about wiring the clock and radio to keep power to them and they said that was okay.

Terry, how are you shutting down the alternator with the single pole Moroso switch? Are you switching the positive or negative side of the battery? My experience has been that sometimes a single pole switch works, and sometimes it doesn't. Engines will often continue to run (tho sometimes not well...) after the battery is disconnected.

For the rest of you, be aware that NHRA won't allow master switches with a removable key, the on/off lever must be permanently affixed to the switch.

Terry, do you know if NHRA allows dry cell batteries, such as an Odyssey, to be used without a vented battery box?

 

[twr]

Gary,
As I recall, they didn't care what type of battery it was. If there is not a bulkhead between the passenger compartment and where the battery is, it needs to be in a box mounted to the car.

Trying to remember what I did. I think I ran a 4 ga wire from the alternator to the switch and then another 4 ga from the other side back to the under hood fuse block. In addition to that, I have an ott ga wire from the battery to a starter relay that only fires when the key is turned to the start position. The battery is on the same side as the alternator. All I know is I followed the directions and when the switch is turned off, the car shuts down and there's no power.

 

[gmorrell]

OK, so you wired the alternator output lead directly to the battery positive, but used the disconnect switch to interrupt power feed to the main fuse block under the hood. That will work (but you already know this...), the disconnect cuts off power to everything, but the alternator remains connected to the battery so there is no load dump generated when the disconnect stops everything.

One other thing Terry did was run a separate heavy B+ wire from the battery forward to the starter, for just the starter motor. Some of us even move the starter relay back to the trunk by the battery so this heavy lead isn't hot but only during cranking.

Here's a diagram of what Terry did:
http://www.2quicknovas.com/trunkbat3.jpg

One thing to consider is adding a fused (1A is plenty) wire from battery + to the dash area so you can feed the radio memory, clock and EEC pin 1, which is the keep alive memory supply.

 

[twr]

Some of us even move the starter relay back to the trunk by the battery so this heavy lead isn't hot but only during cranking.

Here's a diagram of what Terry did:
http://www.2quicknovas.com/trunkbat3.jpg

One thing to consider is adding a fused (1A is plenty) wire from battery + to the dash area so you can feed the radio memory, clock and EEC pin 1, which is the keep alive memory supply.

The link that Gary provided is exactly what I did.

Since mine is a 95, moving the starter relay was not an option. I just got a generic starter relay and mounted it in the trunk. At some point I will add a fused power source forward. Not that it's a pain to reprogram the clock and radio, but if I don't have to....

 

[SHOZ123]

FWIW I use a 350A inline fuse on the cable at the battery.