Yes!!!

Let me clear this upa little better ..I was talking about the emergency cut off switch on the back of our cars. They have them now to hook up the the alt to it but think it's only rated at 20 amps...

I don't see what the problem is wiring the alternator directly to the battery outside of the main kill switch. If you're concerned about it in event of a wreck, put a high amperage fuse or circuit breaker in line with it.

John, it's in the nhra rule book..

"..must break the positive side battery supply.." is what it says. The battery doesn't supply the alternator! Yeah, I know how that is interpreted but remember what the function of that switch is - to kill the car, fuel supply and other devices in event of a wreck/fire for driver safety. There is no danger that I can envision by hooking the alternator (only) direct to the battery, especially if equipped with an in line circuit breaker or fuse.

I've never been through a NHRA national event tech myself, but on the stuff we run around here nobody in all the years I've ran my car has even TESTED my shut off switch, let alone look at how it was wired. Mine works, it kills the car and it shuts all the fuel etc down like it's supposed to. I even go a step further and I put a secondary kill switch by the drivers seat so I can shut the car down from inside the car with one switch - why? Because you can not count on other people doing that for you in the event of a wreck or fire, period.

Bottom line NHRA/IHRA ought to address the issue of how to wire the alternator and what is ok and isn't, but they haven't. It's up to the individual tech inspector to decide that. And you know what 99.9999% are going to do? They are going to have you start the car up, then they'll slap that switch and see if it kills the car, fuel pumps, etc.

You make your own decisions on how you want to wire up the alternator - just make sure the kill switch functions as intended.

Correct...but incorrect! The Moroso switches are only rated for 20 amps on the alternator side. They have 2 3/8 post and two 10/32 posts. The part number I supplied gives you 4 3/8 posts that are rated for 175 amps continuous and 750 amps for 15 seconds.

I agree John...this discussion has came up a lot on other boards...with a lot of different concerns. With the alternator's wired directly to the battery, there is no way to completely isolate the battery from the car. Some racers are also experiencing a drain on the batteries during the week between races...again, the switch would isolate the problem. In the event of an accident, or even a shorted alternator cable....a fuse is the true answer in protecting our investments.

Something I used to use for the alternator at one time, back when I had one, was a forklift circuit breaker. It has a little button you can push it to disconnect the circuit. Works real nice for weekly storage, etc. high current also

Looks like this

Hey thanks for all the reply's and info. It has become an interesting thread.

I have a cole hersee p/n 24812 that was recomened for my application by Texas ind. ele. I talked to Steve there and he said that the relay I now have is the same one that Jerry Haas and Jerry Bickel order all the time from them. If it's good enough for those two guy's it's good enough for my.

This relay will be used as a switch and here are the specs.

12 Volt Continuous Duty
Special Applications: USED AS BATTERY
DISCONNECT SWITCH AND FOR EXTRA HEAVY DUTY ELECTRICAL LOADS.
USED IN MANY EMERGENCY VEHICLES APPLICATIONS LIKE,AMBULANCES,FIRE TRUCKS .
Amps: 225
Coil Type: Isolated
Coil Volts DC: 12 DC
Contact Form: SPNO
Contact Material: Copper
Duty Cycle: Continuous 225 amps; 1000 amps spike


I have a Flamming River push/pull 300 amp continuous use, 1000 amp spike switch for the back of the car. I also have a switch that will be next to the drivers seat. I hope to be able to shut the car down with eather switch and kill (fuel pumps, ignition, ect. ect.). What I came up with was the relay or (switch relay) to aid in that function.

I watched Kenny Esners King of the hill ( KOTH ) car burn to the ground last year because the switch at the back of the car was not shut off quickly enough. There is a video on it. Flames 25 ft in the air.
Now I don't have a 738 ci motor and 3 stages of nitrous with 3 fuel pumps but I do want to save my car from Kenny's kind of loss.

Here's the link to to the video. Notice that on one shuts off the power in the video.

http://videos.streetfire.net/video/Esne ... 163390.htm

So my thinking is, as long as both switches will kill all I will be happy.