nhra killswitch help!

XxWhiteNeonxX · Post by **XxWhiteNeonxX** » Wed Apr 04, 2012 9:16 pm

i have my nhra killswitch done, but i was wondering if i should have an inline fuse on my alternator wire going to the killswitch? If so, what amperage..

-Cody

XxWhiteNeonxX · Post by **XxWhiteNeonxX** » Thu Apr 05, 2012 10:05 pm

anybody?

ZeroChad · Post by **ZeroChad** » Fri Apr 06, 2012 12:18 am

Yes, you would want a fuse between it and your battery. Did you do the rear mount battery relocation? Where is your current fuse located for it, between the switch and the battery?

XxWhiteNeonxX · Post by **XxWhiteNeonxX** » Fri Apr 06, 2012 7:28 am

ZeroChad wrote:Yes, you would want a fuse between it and your battery. Did you do the rear mount battery relocation? Where is your current fuse located for it, between the switch and the battery?

battery is in the trunk. The fuse ( 200a) is located in the trunk as well.

what amp fuse would i want for the one coming from the alternator? and which side of the wire would i want it on ?

Post by **occasional demons** » Fri Apr 06, 2012 9:38 am

XxWhiteNeonxX wrote: what amp fuse would i want for the one coming from the alternator? and which side of the wire would i want it on ?

If this is for fire prevention, you would optimally want a fuse on both ends. But the battery end would be the bigger priority. IDK how well the alternator can melt a wire on it's own, before it failed. But anything is possible. Not worth the risk IMHO.

If the car is stripped to the basics, you could prolly get away with a lighter duty fuse, since you are not running a high electrical demand. It would blow sooner in the event of a major short. You just couldn't put a near dead battery in, and expect it to not blow the fuse. But that would be counter productive to ET's trying to recharge a battery.

So as long as you keep a good battery in it, you would be fine with ~80 amp fuse, maybe less.

ZeroChad · Post by **ZeroChad** » Fri Apr 06, 2012 3:57 pm

Where is your current fuse located for it, between the switch and the battery?

or between the switch and fuse box?

XxWhiteNeonxX · Post by **XxWhiteNeonxX** » Fri Apr 06, 2012 5:55 pm

ZeroChad wrote:
Where is your current fuse located for it, between the switch and the battery?
or between the switch and fuse box?

ok, long story short i relocated the battery to the trunk.. i bought an nrha vented battery box and an nhra killswitch. I wired everything up except the alternator wire ( its needed to cut complete power to everything instead of just battery power)

So, i have the battery wiring going to the front of the car ( fuse box) ( 200a fuse in trunk located beside battery) but i need to run the alternator wire now and before i get it all up and running, i want a fuse on it but i was unsure of size and such.

ZeroChad · Post by **ZeroChad** » Fri Apr 06, 2012 7:49 pm

Right. And what I was getting at is that you could use one fuse for both purposes if wired up correctly.

Wouldn't you have one wire going to the cuttoff from the battery and then from there it Ys to the alternator and battery? In this case, fusing the line between the battery and the switch covers you in both cases. Like Bill suggested, butting an additional fuse near the alternator gives you extra fire protection.

XxWhiteNeonxX · Post by **XxWhiteNeonxX** » Fri Apr 06, 2012 9:56 pm

ZeroChad wrote:Right. And what I was getting at is that you could use one fuse for both purposes if wired up correctly.

Wouldn't you have one wire going to the cuttoff from the battery and then from there it Ys to the alternator and battery? In this case, fusing the line between the battery and the switch covers you in both cases. Like Bill suggested, butting an additional fuse near the alternator gives you extra fire protection.

i have the 200amp fuse on the fuse box side of the switch ( in the trunk, not at the actual fuse box)

so, ive been told that the alt wire goes on the battery side of the switch so when it shuts off, it kills power to the alternator and the battery. If its on the battery side though, wouldnt the battery provide power to the alternator even with the switch off?

-Cody

Danteneon · Post by **Danteneon** » Sat Apr 07, 2012 12:05 pm

XxWhiteNeonxX wrote:so, ive been told that the alt wire goes on the battery side of the switch so when it shuts off, it kills power to the alternator and the battery. If its on the battery side though, wouldnt the battery provide power to the alternator even with the switch off?

-Cody

Wired like that, yes it would. How about this...

Battery...Fuse...Kill switch...the rest of your system that you already have

Once the switch is set to off, the current is only running to the one side of the switch. The rest of the car is dead.