17 replies to this topic

[Tiny]

Gday Again!

Just something else i've gotto work through in my mind....

I've got a -ve isolator in the main battery cable. This is fantastic for when the car is parked.. nothing drains the battery. However if the car is running and you remove the key ( opening the switch and isolating the battery) the car keeps running!

Is this because the body/chassis is already at -ve potential and thus we still have circuits active? Or what is the reason behind this?

I would have thought ( Hoped!) that the instant you remove the switch the car would shut off instantly.

Is there any simple way with a battery mounted in the boot do achieve this? or do i need to look at solenoids to ignition feeds and this kind of thing?

Cheers in advance (IF anyone is game to reply after my last threads! LOL!)

[rodomo]

I'll have a punt.

It runs because your alt is charging. I assume your big alt wire joins the main batt+ at the starter? And your ignition feed to the dash comes off there too?

You would have to isolate the pos+ (alot easier than trying to isolate all the negs-)and run the wire that feeds your ignition from the isolator rather than the starter.

This way, when you turn off the isolator it will cut the ignition supply.

I think

[FastEHHolden]

word.

[VitcLJ]

Rodomo is right. The altenator is still charging and unfortunately connected to -ve via the case and of course the wiring is normal and still connected to +ve as well via the main output wire. Its unusual to have the isolator in the -ve side mind you if you put it in the +ve side with the wire from the altenator going to the starter solenoid connection as per normal the same thing would happen. You need to wire the altenator output directly to the battery so when operarting the isolator it also disconnects the wire from the altenator to the rest of the circuits. This works real well and does stop battery drain unless the altenator is crook but I guess thats not a problem as you then find out the altenator is faulty and fix it. This is the most common way of providing isolation.

[Tiny]

Thank you very much Gents!

I sort of thought as much, but i thought best to speak to the Gurus we have here

Cheers!

[Struggler]

Hi Tiny, everything these guys have said is correct.

Also note running the alt wire to the battery will cut the engine out but the alt wire will still be live.

Current ANDRA regs state that isolating the battery must stop the engine running and isolate all power in the vehicle. To get around this you really need a 6 pin isolation switch like they use in touring cars.

This is the one I ended up getting.... http://www.revolutio...amp;PSV=Primary

This requires you to run the coil wiring down to the switch and back.

[Tiny]

Wow What a pain! Is that why they often mount the switch up near the cowl? to minimise the coil to switch length?

Considering i've got everything pulled apart now I wonder if now might be the time to integrate this? Does it still run on the -ve side of the battery, but also the coil wire?

(would it be possible to get a quick rundown on how it's wired into the car!)

Thanks Struggler!

[Struggler]

It goes in the Pos. battery cable.

6 terminals are as follows....

2 terminals are the same as before (batt. power in and out)
1 power in (jump from the switched power terminal)
1 earthed thru supplied resistor
1 switched power from ignition switch
1 power back to coil.

[Tiny]

Awesome, Thanks again Struggler, I might look in to fitting this while i'm stuffing around with it all!

Cheers

[Tiny]

That would need another big Relay greg? (120A capacity!)

[rodomo]

That would need another big Relay greg? (120A capacity!)

The starter solenoid Greg speaks of is the big relay.

[Tiny]

Ohhhhhhhhhh

I Geddit!

[Struggler]

OR...
you can run your main power feed from the alt to the starter VIA another starter solenoid that is energised ONLY when the isolator is tuned ON....
This way saves some duplicating of wires. Also kills the engine and the alt wire is dead as well.

Cheers Greg..

Right you are. I have seen this done as well using a Ford remote starter solenoid located near the batt. box (the alt. charge wire was running all the way back to the battery).