another master kill question

[ewaugh]

I read this out of a thread I found in a search about wiring up a master kill

I wired my car (1990 CRX Si) as such:

Remove the large white wire from the alternator (output wire) and from the main fuse panel in the engine compartment. You can remove this wire completly from the wiring harness if you wish, I did, in order to ensure that it did not splice or "t" to any other circuits. It didn't.

Remove the stock battery (+) cable that goes from the battery to the main fuse panel and to the starter. Disconnect all three connections. Again, discard, if you wish. I removed the crimp on battery terminal from this wire and re-used it.

Install a white wire (or any colour you wish) from the alternator to one side of the disconnect switch. I used #10 wire, 12 or 14 is probably fine.

To the same side of the disconnect switch, run a red wire from the positive battery terminal. I used #6 wire, #8 is likely OK, Honda starters don't require a lot of juice.

From the OTHER side of the disconnect switch, run another large red wire to the starter.

From the starter, run another short wire (#10 is likely fine, I used #6) to the main fuse panel and connect it to the left terminal. This terminal is fused through the 60a main fuse, the other one (now unused) is not fused through the main fuse.

That does it!

To summarize, both possible sources of power (battery and alternator) are disconnected and isolated from the rest of the car through the switch. Any consumer of power, including alternator excitation, fuel pump, ignition, etc. is completely cut off by the switch.

Also, there is a path for the alternator current to flow to (momentarily) when you activate (move to OFF position) the switch, through the battery, which protects the alternator diodes.

I think that's it...[/b]

I tried something similar and killed a battery. The hypothesis is that I was backfeeding the alternator becasue I had the alternator and battery tied togeatehr on the same terminal. If I put the alternator on the same terminal as the ecu and main then it doesn't kill the motor. I have seen a few drawinga that show it this way though, including the one above. Any ideas?

[JoshS]

Such a wiring approach does not meet the letter of the rules.

The master switch shall be installed directly in
either battery cable and shall cut all electrical circuits but
not an on-board fire system.[/b]

If the battery is still connected to the alternator, then you haven't cut all circuits.

[ewaugh]

Here's what I did:

Battery positive to A side of switch

Alternator hot to B pole of ford starter solenoid

Alternator hot from M pole of ford starter solenoid to B pole of switch

From B pole of switch to Main under hood.

Pull a wire off...anything thats hot while the ignition is on to close the solenoid. Flip the switch and the soleniod opens. Alternator power drains to frame.

Ay ideas on the starter? I have it straight to the battery now, which I know is wrong. Should I pull another wire off the switch to the starter?

[JoshS]

You need one of these:

http://www.pegasusautoracing.com/productde....asp?RecId=1464



On some cars it's a little tricky to find something to use for the Z circuit on the switch, but it's always possible.