I got a CRX and I'm moving the battery to the trunk area, I got a NHRA approved box, now I'm looking for a disconnect switch. I was wonder can you use a disconnect switch for the negative side instead of the positive side, since it still disconnects everything.

Also, can I have my alternator output wire go to the starter terminal (my fuse box is under my dash)? Since the only draw will be when it's starting and the alternator isn't working then anyway, and when it's running the alternator it on and starter isn't drawing anything (and the power from alternator just goes back to the battery).

Also, if a disconnect switch doesn't say NHRA approved is it still good? I know those cheap plastic ones probably aren't approved, but what about the nice metal ones.

 

Im not the best to give advice, but I believe, once the car is running off of the alternator, not the battery, killing the battery/negative wont do anything. It will stay running. You have to disconnect the power and alternator with the switch.

Only thing that I know about the switch, is it cant be plastic. Has to be metal. Dont know what switch you are referring to, but its probably ok.

 

Okay, but if the car is running and you disconnect the negitive side then the fuel pump, ignition and everything else wouldn't work so how could it stay running? Guess I will pick up a nice sturdy metal switch.

 

When you disconnect the negative on the battery, then the alternator is powering the car. The battery is basically just a capacitor in parallel to the system. The actual negative would be back at the alternator, since electricity returns to its source.

BTW, I believe I bought one from Jegs. It wasnt that expensive and rated for plenty of current.

 

So, basically it would have to be positive side. Is 100 amps steady good enough? Or do I need 175 amps?

 

Isn't the OEM battery fuse 80amps? I would think 100amps would be sufficient or am I confused?

 

Yes it is, some are even 60 amps. I never really thought of that, yeah so I guess it is okay at 100amps.

 

I break the ignitor wire on my ecu with the switch

 

thats pretty much how mine works. but i kill the power to the fuse box which kills the ECU.

 

i put mine on the positive battery cable and it did not kill the car. i put the switch inline with my ignition switch

 

gonna bring this back and ask does nhra say you have to kill battery power and the car or just has to cut off engine?

 

https://honda-tech.com/forums/drag-racing-36/wiring-diagram-battery-relocation-master-kill-switch-1980854/
https://honda-tech.com/forums/drag-racing-36/battery-kill-switch-pics-2629798/