Help help, installed kill switch

[Lenie]

My battery is in the trunk, had american auto wire install, their 10 guage wire went from my one wire alternator to the starter. I decided to install a big switch flaming river kill switch in the trunk, so what I did was disconnect and remove the 10 gage wire from the alternator to the starter and installed a 4 guage wire from the alternator straight back to the kill switch in the trunk to the battery side on the other side of the kill switch I connected the 0 gage wire from the starter. Here's my problem, before I began the switch the car started and ran perfect and now that I'm finished the car has a hard time starting, acts like it's flooded, runs really rough for a couple of seconds and dies. Any ideas? Here's a diagram I used for running the alternator wire to the kill switch in the trunk. Thanks

http://img585.imageshack.us/img585/7913/8565.jpg (http://imageshack.us/photo/my-images/585/8565.jpg/)

[Musclerodz]

If you only messed with the positive cable and not any negative cables the issue is either your new kill switch or the alternator is not working. It sounds your not getting enough voltage to keep the ecu happy. check the output voltage of the alternator, and if its good, there has to be an internal issue with the kill switch.

[Che70velle]

Lenie, did you interrupt any grounding means during this swap? Does the starter turn slowly?

[Che70velle]

Upon thinking about this a little, are you sure that you put the cutoff switch on the correct wire? I've always installed my cutoff switches on the ground circuit, instead of the positive battery wire. It removes all load from the switch.
I'm not saying it won't work the way you have it wired, I've just never done it that way.

[GregWeld]

Upon thinking about this a little, are you sure that you put the cutoff switch on the correct wire? I've always installed my cutoff switches on the ground circuit, instead of the positive battery wire. It removes all load from the switch.
I'm not saying it won't work the way you have it wired, I've just never done it that way.




Totally agree with using only the ground for killing stuff -- never the positive side!

[Musclerodz]

Dumb me didn't pay close enough attention to your diagram on how you hooked it up. As others have stated, I would move the kill switch to the negative side, but if there is still an internal issue with the switch, it will still cause issues. I did go to Flaming Rivers site and they show the switches to be load rated, but always safer to switch grounds.

[Lenie]

Thanks everyone, I did disconnect the negative and positive while installing, in the morning I'll switch it over to ground and see what happens. Appreciate the quick responses, I am an electrical dummy!

[DRJDVM's '69]

Take the switch out and connect the 2 wires.... If the issue is gone, it's the switch itself, not the location in the circuit

[Lenie]

Bingo, thanks Ned.

[ErikLS2]

I'm late to the party as usual here but it doesn't remove the "load" from the switch to have it on the ground side, it just removes the voltage from it as the "load" in the circuit (bulb, starter, computer, etc.) uses up the voltage before it gets there. Amperage though is the same throughout the circuit, power or ground side. Most vehicle manufacturers place switches on the ground side as the lower voltage reduces the very minor arcing across the contact points (where there isn't a transistor these days) caused by the additional voltage going through it and in theory making the switch last longer.

If removing the kill switch didn't solve the problem check for voltage loss across all the wires in the circuit. This is important, do it with the circuit operating. Set your meter to volts and connect it to each end of any wire you want to check. In your case each end of each black and red wire as well as across the kill switch contacts and alternator wire. On the large gauge wires going to the starter you'll have to disable the ignition system and measure it while cranking. I would pay special attention to the wire from the alternator (it might be too small for that span) and on this one the engine will have to be running, if it will run, if not while cranking will have to do. You should read very little voltage in any of these test, not more than 0.1-0.2 volts is ideal, if more than say a volt there's way too much resistance in the circuit or the wire is too small in diameter.

[DRJDVM's '69]

KISS...keep it simple stupid..:)

So then the debate comes back to, which side to run the switch.... my understanding is that it really depends on what your goal is.

If the goal is to cut all power in the event of a crash etc, so none of the electrical systems have juice flowing through them, then it should be close to the BAT and on the positive side. If you crash and things are all mangled, you may have created new ground points all over the place with shorted wires...and you don't want a bunch of hot circuits anymore

If the goal is more to be able to just essentially disconnect your BAT when the car is sitting, so the BAT does constantly get drained, then just put it on the NEG side

[waynieZ]

As for the negative being switched, couldn't the starter get a dead short and cause a fire if it the positive was hot ??

[Lenie]

Disconnected from kill switch straight to battery, nothing. Decided to rewire back to original set up straight from 1 wire alternator to starter, still nothing. I believe I've done something to fry my msd 6al 6420 ignition box (must of spiked it)...no fuse..really...crap. Guess I'll buy another....hmmm cars

[waynieZ]

What would Greg Weld say That's hot rodding! Still hurts though doesn't it.
I hope you get it figured out.

[Lenie]

What would Greg Weld say That's hot rodding! Still hurts though doesn't it.
I hope you get it figured out.

Ya just like Greg, trying to make this hobby fun!:lol:

[Lenie]

Took the long road there but got er' fixed!:whistling:

[GregWeld]

Spill your guts matey!


Did ya LEARN something along the way -- because that's the best part of screwing something up is if you "get it" when you're done?


XOXO
Greg

[Lenie]

Ya Greg, everything I do on this car I learn something new and lovin' it. A little embarrassing, probably should have been the first place to look but it was my last, you know spark, air and gas. I was changing to a bigger alternator wire to a kill switch so after I was done and it didn't start, I thought it was electrical, something I screwed up and got it stuck in my head that was the problem. I started by buying a new battery, then put everything back the way it was, didn't work, moved the ground to the kill switch instead of positive, didn't work, installed a new coil, didn't work, installed a new msd 6al box didn't work, redid all my grounds, didn't work, keep in mind I've only driven this thing about 5 miles, put a volt meter to the distributor and it checked out fine, checked everything for spark and all was good, pretty puzzled at this time and reading everything on google there was about msd issues. Got to talking to one of our mechanics at work and he says Lenie, I know you haven't driven the car much but it comes down to spark, air and gas....put a new cap and rotor on and change out the spark plugs while your at it and see what happens.....so I changed them out and bingo, starts up the first time she turns over. Funny how the mind works when you get stuck on something and don't look at the big picture... live and learn. Car goes to the upholstery shop first week of October, said they'd have it about 10 days and be done. I missed the summer but finally the car will be pretty much finished:happy23:

[waynieZ]

Lenie Don't feel bad I usually take the round about way to get things figured out too. Glad you fixed it and its going to the interior shop.
It won't be long now !

[Ron in SoCal]

Lenie please don't feel bad. I go through this crap all the time! Latest project f-up was a fuel issue on my boat. Two fuel pumps, a fuel pump push rod, fuel log return valve and a redo of the tank pick up I finally replaced the non-ptfe return line. Dog fired right up.

Us non-pros learn a lesson each time we open the tool box. Fun huh? :)

[intocarss]

KISS...keep it simple stupid..:)

So then the debate comes back to, which side to run the switch.... my understanding is that it really depends on what your goal is.

If the goal is to cut all power in the event of a crash etc, so none of the electrical systems have juice flowing through them, then it should be close to the BAT and on the positive side. If you crash and things are all mangled, you may have created new ground points all over the place with shorted wires...and you don't want a bunch of hot circuits anymore

If the goal is more to be able to just essentially disconnect your BAT when the car is sitting, so the BAT does constantly get drained, then just put it on the NEG side ^^^THIS^^^^

[Che70velle]

I'm failing to follow the logic of a couple posts here.
If I put my cutoff switch on the power side of the battery, it will absolutely see all the load that the vehicle is using. The power side, or positive side of the battery's circuit produces, or sees, the load. Lets say I'm using a cutoff switch rated for 50 amps, and my vehicle's electronics need more than the switch is rated for. The switch will eventually overheat and fail. Doesn't matter if you've rated the cables correctly, the switch will be the weak link. Ok, let's look at it from another view. Even if the switch is overrated for the vehicles load demands, and there is an accident that produces a short on the positive side of the battery, the switch will be the weak leak and fail. That's a good thing, as long sat the switch can be closed quickly, but what if it overheats and sticks closed, meaning you cannot open the switch? Not good. If the ground side of the circuit sees as much load as the power side, then why not fuse the grounds, and not the hot side? The ground side will see the voltage, but not the amperage, because the amperage is used by whatever is pulling it. You cannot push electricity. It has to be pulled.
So what if I place the switch on the negative side of the battery? First off, it does not see a load, and will never fail from overloading, and best of all if you remove the ground from the vehicle by switching the negative cable off, then there is never a chance of circuits becoming energized if the switch is off, meaning no "juice" can flow through them, because electricity has to have a ground, or you don't have electricity to start with. I've wired many race cars, and street cars, with cutoff switches, and believe me your taking an unnecessary risk by putting the master cutoff switch on the positive side. Will it work? Sure. Play it safe, and switch the negative side. No ground equals no power.
Did I tell you guys that I make a pretty good living messing with electricity?

[GregWeld]

Scott --- I told him that 15 posts ago..... HAHAHAHAHAHA



Once people actually UNDERSTAND electricity - it all makes more sense....



It's like a buddy of mine when I was trying to show him that he didn't need to run a ground wire from another ground wire and that the shortest path to ground was the best choice.... I still don't think he understood. It's only - he doesn't get the whole RELAY thing either! HAHAHAHAHAHA

[GregWeld]

Think of it like this ------



You have "hot" going all over the car to run many items.... but if they aren't seeing the ground side -- then they aren't hot! Real simple.



Take a battery cable -- run it to the hot side of the battery (12V +) -- never hook up the ground side of the battery.... run around with the 12V hot wire and touch all over the car - and you'll never have a spark. Why? Because there's no path to ground.

[Che70velle]

Yeah Greg, I follow you. Relays are fun. I've always said the easiest way to confuse a "smart" person is to throw a relay into the conversation.

[Che70velle]

Think of it like this ------



You have "hot" going all over the car to run many items.... but if they aren't seeing the ground side -- then they aren't hot! Real simple.



Take a battery cable -- run it to the hot side of the battery (12V +) -- never hook up the ground side of the battery.... run around with the 12V hot wire and touch all over the car - and you'll never have a spark. Why? Because there's no path to ground.

Exactly!

[DRJDVM's '69]

But as a safety switch....i.e, you crash the car and need to shut it all off....isn't there a good chance you just created some new grounds when the car is all mangled?

[Che70velle]

That's what fuses are for. They blow, or trip depending on which style you use, if there is a short, from a possible wreck, or whatever, or there is overloading, meaning the current draw in the circuit is more than the fuse is rated for.

The beauty of putting the master cutoff in the negative side of the battery is that it can't fail from overloading, and when you turn it to off, there are no grounding points on the vehicle. No grounds equals no power. Anywhere.

If a vehicle is wired without fuses, it is a problem waiting to happen. I don't care if its a racecar with 3 circuits in the entire vehicle. Always use fuses.

[seankc31]

If you connect the battery ground DIRECTLY too the switch only (maybe make sure the switch isolated too) then too frame...when you kill switch it will isolate everything part of that main circuit and its all parallel circuits(from - battery to load to +battery) because the circuit is incomplete so no power will flow... so even if u touch a power wire to a ground nothing will happen because no power is flowing with (switch off)..just make sure all circuits tap off main circuit... same idea as putting it the postive side but you would need switch rated to handle all the amps the car will need (including start up :welcome3:

But as a safety switch....i.e, you crash the car and need to shut it all off....isn't there a good chance you just created some new grounds when the car is all mangled?