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BOZ22N

Wiring Up A Cams Approved Batt Isolator

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Riteo,

I have been building up R33 up as a track car for a while now and i am in the final stages of it. I am trying to sort out the wiring as well as fitting a CAMS approved isolator. They have to be a 6 pole isolator that protects the alternator from current surges etc once it has been switched off etc, the diagram i got with it is below. I am confused with a few of the wires and why the 3 Ohm resistor is required. I am ok with wiring up the main battery cable the positive jumper and the resistor but i am a little confused with the Ignition switch wire and the ignition coil wire. Do you just splice into the ON wire on the back of the key or do you have to cut the wire so to stop the std battery feed? for the ignition coil wire can i just tap into the ignition wire that used to go into the old dash? As i am running a Stack dash this plug is just cable tied back onto the harness.

Also i was thinking cause i am running the Stack dash will i have to wire in a Battery/alternator light in so that the circuit is complete and the alternator will still be excited and charge?

I was hoping that some electrical gurus could clear this up so that i can power up my car and the info will be on here for other's.

Thanks Ryan

MasterSwitch_.pdf

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Riteo,

I have been building up R33 up as a track car for a while now and i am in the final stages of it. I am trying to sort out the wiring as well as fitting a CAMS approved isolator. They have to be a 6 pole isolator that protects the alternator from current surges etc once it has been switched off etc, the diagram i got with it is below. I am confused with a few of the wires and why the 3 Ohm resistor is required. I am ok with wiring up the main battery cable the positive jumper and the resistor but i am a little confused with the Ignition switch wire and the ignition coil wire. Do you just splice into the ON wire on the back of the key or do you have to cut the wire so to stop the std battery feed? for the ignition coil wire can i just tap into the ignition wire that used to go into the old dash? As i am running a Stack dash this plug is just cable tied back onto the harness.

Also i was thinking cause i am running the Stack dash will i have to wire in a Battery/alternator light in so that the circuit is complete and the alternator will still be excited and charge?

I was hoping that some electrical gurus could clear this up so that i can power up my car and the info will be on here for other's.

BUY A HELLA ISOLATOR AND DONT USE THE UNIT WITH THE RELAY THEY CAUSE MORE ELECTRICAL ISSUES THAN U CAN IMAGINE), HOOK THE BATTERY FEED TO ONE SIDE, RUN THE BATT (+) ALTERNATOR MAIN FEED TO THIS SIDE TOO (DISCONNECT THE ORIGINAL 6MM WIRE AT THE BATT (+) POST OF ALTERNATOR) MAKE SURE YOU USE A 100 AMP HD FUZE OR FUZABLE LINK IN THIS 6MM CABLE. THEN ON THE OTHER SIDE OF THE SWITCH RUN IT TO THE STARTER LUG AND INTO THE FEED OF THE FUSE BOX RH SIDE OF ENGINE BAY. WHEN YOU TURN THE ISOLATOR OFF THE CAR STOPS BUT LEAVES THE OUTPUT TO ALTERNATOR SIT CONNECTED TO BATTERY SO NO CURRENT SURGE OCCURS. IT WILL REQUIRE A PULL CABLE TO OUTSIDE AND HAS TO BE ABLE TO BE REACHED INSIDE BY DRIVER AND NAVIGATOR. I THINK THE RULING ON OUTSIDE PULL LOCATION IS STILL RH SCUTTLE PANEL? AREA.

Thanks Ryan

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looks hard!

I hooked the standard fuseable link to the input to a 80a relay (pin 30). Output goes to where the fuseable link went stock (pin 87)

Second wire from the battery to the relay (86)

Earth for the relay (85) to a kill switch on the dash, then earthed after the switch.

Dead simple. And the only problem is the relay will drain the battery after a week or 2 if you don't turn it off at the kills switch when you stop the car....but this is a good habit anyway

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Thanks Brad but now i am even more confused? I have read it a few times and i still don't get it 100%

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Thanks Duncan,

Are you calling the positive battery cable the fuse able link?

So you just run a big relay in the boot with the switch for it in the dash?

So in three posts i have three different ways hmmmmmmmm.

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standard setup has 3 cables to the battery

starter motor

alternator

everything else.

i cut power to "everything else" it stops the car which stops the alternator.

It does mean the starter is not "isolated"....but then again I have a front mounted battery. If you only have 1 cable to the battery it will be tricky....starter motor draws 11ty billion amps so you can't run it thru most relays (or most fuses or circuit breakers for that matter). It is not fused from the factory

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Thanks Duncan,

Are you calling the positive battery cable the fuse able link?

So you just run a big relay in the boot with the switch for it in the dash?

So in three posts i have three different ways hmmmmmmmm.

WHICH BIT DONT YOU UNDERSTAND?

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standard setup has 3 cables to the battery

starter motor

alternator

everything else.

i cut power to "everything else" it stops the car which stops the alternator.

It does mean the starter is not "isolated"....but then again I have a front mounted battery. If you only have 1 cable to the battery it will be tricky....starter motor draws 11ty billion amps so you can't run it thru most relays (or most fuses or circuit breakers for that matter). It is not fused from the factory

Yer my battery is in the boot with only two cables so the relay idea will not work

WHICH BIT DONT YOU UNDERSTAND?

My car is a R33 and the battery is in the boot with only the two cables so will i have to run cables from the engine bay? Are you talking about an R32?

HOOK THE BATTERY FEED TO ONE SIDE Are for getting this off the alternator?

RUN THE BATT (+) ALTERNATOR MAIN FEED TO THIS SIDE TOO (DISCONNECT THE ORIGINAL 6MM WIRE AT THE BATT (+) POST OF ALTERNATOR) MAKE SURE YOU USE A 100 AMP HD FUZE OR FUZABLE LINK IN THIS 6MM CABLE. Is this the positive lead off the battery?

THEN ON THE OTHER SIDE OF THE SWITCH RUN IT TO THE STARTER LUG AND INTO THE FEED OF THE FUSE BOX RH SIDE OF ENGINE BAY

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Im onto this.

Its hard to understand brad because he spells Fuse FUZE. Geez.

my mac doesnt have paint as im afraid its far to superior.

this is a hand drawn diagram of the best way to do race car isolation. i have done 20+ cars this way and saves using the gay cams spec way and as brad says it will cause you trouble in the long run.

use a hella 2 pole iso switch. no cheap alternatives and a good quality fuse link.

ill post some pics up tomorrow after working on bens race car.

DSC03047.jpg

so on a r33 id put the iso switch in the boot with a cams compliant pull cable near the bottom right of the windscreen then id run a second pull cord to the dash for your own safety.

put all the battery positive wiring to one side of the iso switch. make a short battery cable to go between the iso switch and and batter positive.

then remove and insulate the battery wire going to the alt. run a new wire. 8 B&S cable for a long run. from the batt stud on the alternator to the battery positive side of the iso switch VIA a 100A fuse link.

on R32s the 2 pin plug that goes into the alt contains a Voltage sense wire and a warning light feed. the Voltage sense wire is spliced into the wire running from the battery stud on the alt to battery positive. im unsure about r33s but if you only cut and insulate the standard r33 battery feed to the alt, when you add in the iso switch you wont upset Voltage sense wire.

hope that helps

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Thanks Damo,

That sounds good but does that mean that when the switch is turned off the alt will still be able to send a voltage spike to the battery and the electronics? Should the alternator + wire be on the same side as the s/motor so to keep any voltage spikes away from the battery and the electronics?

Also you did not have any wires going to the main fuse panel to power the car electronics? The R33 has a small jumper cable in the boot from the battery to the fuse panel where would you run yours?

I also have a Mac so i have draw you a little picture of what my idea is/was? Let me know if i am going the wrong way about it.

Isolator01.jpg

Cheers,

Ryan

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now you've got me confuzzled damo. In your pic only the starter motor is turned off then the switch is off? Or have you left the rest of the car's wiring off the pic?

BTW ditch the mac get a PC. macs are rubbish if they don't have mspaint

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now you've got me confuzzled damo. In your pic only the starter motor is turned off then the switch is off? Or have you left the rest of the car's wiring off the pic?

BTW ditch the mac get a PC. macs are rubbish if they don't have mspaint

damo gets his blow up dolly confused too

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Thanks Damo,

That sounds good but does that mean that when the switch is turned off the alt will still be able to send a voltage spike to the battery and the electronics? Should the alternator + wire be on the same side as the s/motor so to keep any voltage spikes away from the battery and the electronics?

Also you did not have any wires going to the main fuse panel to power the car electronics? The R33 has a small jumper cable in the boot from the battery to the fuse panel where would you run yours?

I also have a Mac so i have draw you a little picture of what my idea is/was? Let me know if i am going the wrong way about it.

Isolator01.jpg

Cheers,

Ryan

Ok i didnt add in the other stuff as i thought you was only confused about the alternator wiring and didnt want to clutter it all.

the pic above is wrong and dont do it like that or you will have trouble.

Firstly you wont get a voltage spike when you turn the isolator off when wired the way ive shown you. if you did it would be absorbed by the battery anyway as they are like a giant capacitor.

have a look at the revised diagram and see if that helps.

DSC03048.jpg

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Doesn't the isolator switch need to cut power to the alt so that the car stops dead when you flick the kill switch.....if that is what you are trying to achieve?

In you latest diag this won't happen and the alt will keep powering the ignition system and therefore the engine will keep running when the kill switch is flicked. In your diagram the kill switch will only prevent the car from starting....but not stop it from running.

Scroll down to post #9

http://www.ls1tech.com/forums/drag-racing-...off-switch.html

Shouldn't the fuse wire in the attached diagram link terminate on the other side of the kill switch - as it is its terminating on the same pole as the battery cable therefore providing power to the alt.

Now I'm confused Lol.

Edited by juggernaut1

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Doesn't the isolator switch need to cut power to the alt so that the car stops dead when you flick the kill switch.....if that is what you are trying to achieve?

In you latest diag this won't happen and the alt will keep powering the ignition system and therefore the engine will keep running when the kill switch is flicked. In your diagram the kill switch will only prevent the car from starting....but not stop it from running.

Scroll down to post #9

http://www.ls1tech.com/forums/drag-racing-...off-switch.html

Shouldn't the fuse wire in the attached diagram link terminate on the other side of the kill switch - as it is its terminating on the same pole as the battery cable therefore providing power to the alt.

Now I'm confused Lol.

the reason you are getting confused is that you dont understand the electrical workings of an alternator.

have you ever used a battery to jump start a car (older cars) and then removed that battery and fitted the flat battery back in? when you take the battery out the engine keeps running because the alternator keeps charging. not only does it keep charging but the voltage will spike because it has no voltage reference (the battery) to tell it what voltage to regulate at.

if you dont put the main battery feed off the alternator onto the battery side of the isolator than when the kill switch is turned off the engine keeps running because the alternator keeps charging.

So in summary you keep the battery positive of the alternator and the battery positive of the battery on one side of the isolation switch and all the other wiring on the electronics side and it stops the completion of a circuit. the whole aim is to stop the completion of a circuit from anything that can produce a voltage. ie battery or alternator.

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but....the alternator will stop charging because the engine will stop because the ECU/fuel pump/injectors will loose their power?

The method I first said above is effectively the same, 32 GTR has 3 wires to the battery (alternator - no cut, starter - no cut, everything else - kill switch)

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OK thanks Damo, i got it now.

I read it as the alt needs to be isolated from the whole system in the case of an emergency shut down, but it just needs to be isolated from the electrics and the battery needs to be isolated from the electrics to prevent run on. Your system will work sweet then.

I will post up some pics of how i done this in a R33 for future reference later on.

Thanks again.

Ryan.

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the reason you are getting confused is that you dont understand the electrical workings of an alternator.

have you ever used a battery to jump start a car (older cars) and then removed that battery and fitted the flat battery back in? when you take the battery out the engine keeps running because the alternator keeps charging. not only does it keep charging but the voltage will spike because it has no voltage reference (the battery) to tell it what voltage to regulate at.

if you dont put the main battery feed off the alternator onto the battery side of the isolator than when the kill switch is turned off the engine keeps running because the alternator keeps charging.

So in summary you keep the battery positive of the alternator and the battery positive of the battery on one side of the isolation switch and all the other wiring on the electronics side and it stops the completion of a circuit. the whole aim is to stop the completion of a circuit from anything that can produce a voltage. ie battery or alternator.

Yes I get it now...I was thinking that when they are on the same side the battery also supplies a current to the alternator and therefore the ignition system when the car is not running - i.e. the alternator is still live because of the battery. However, on closer inspection of the diagram link I posted, this is irrelevant because the live feed from the alternator to the fuse box has been cut and removed and replaced so that it is effectively running off the other side (non battery/alt side) of the isolator switch. So all the alternator now does is charge the battery and is no longer used as a source of current to the ignition system or any other electrical system of the car as this part of the system has been removed. I now confirm that the principals in the electrical diagram in the link I posted is correct :(

Edited by juggernaut1

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