Listers:
To everyone that's planning to install a battery cutoff switch, here's a note of
caution.
The generator (or alternator) 'battery' connection should be wired to the same
side of the switch as the battery. I realize (having had to do it) that it's a
pain to run the extra wires around in that direction, but there are two reasons
why:
1. If you are installing the kill switch for racing regulation purposes as well
as anti-theft, then if the kill switch cuts off the battery only, the engine
will keep running because the generator will supply the current to run the fuel
pump and the ignition. You need to cut off both the generator and the battery.
2. If the battery is cut off from the alternator/generator with the engine
running, the voltage spike caused by the load on the alt/gen being removed
(called a 'load dump') can easily reach 100V and persist for 30 or 40
milliseconds. This is sufficient to fry or damage on-board electronics.
Here's yet another fuel pump disabling method: It is not difficult to make the
fuel pump manual-starting. Put a relay in the circuit, with the solenoid
connected to the same side of the contacts as the pump (i.e. the 'output' side).
Wire a pushbutton from the ignition to the solenoid as well. Now the pump is
started by pressing the pushbutton after the ignition is turned on; once the
relay is engaged, it keeps itself energized until the ignition is turned off.
The pushbutton can be located anyplace inobtrusive. Some kind of 'idiot light'
might be useful here to keep you from getting stuck in the middle of an
intersection.
Theo Smit
tsmit@novatel.ca
B382002705
> -----Original Message-----
> From: Bob Palmer [SMTP:rpalmer@ames.ucsd.edu]
> Sent: Saturday, February 20, 1999 7:06 PM
> To: Steve Laifman; Rich Atherton
> Cc: Allan Connell; DJoh797014@aol.com; tigers@autox.team.net
> Subject: Re: Fuel pump switch
>
[] <snip>
> Steve, et Listers,
>
> Now you can install one of those battery switches somewhere, but you
> probably wouldn't want to run that heavy welding cable that runs from the
> trunk to the starter relay over to the ashtray. And speaking of insurance
> companies (fire insurance in this case) has anyone ever heard of that
> battery cable shorting out? I'll bet that could ruin your whole day. I
> installed one of those battery kill switches, although in a rather
> prominent place as required by SCCA, etc. Still, if I take the key with me,
> it would probably take the average thief quite a while to figure out what's
> wrong. But then, the average thief wouldn't be stealing a Tiger, would he?
> More likely a '95 Toyota Camry. How much are Tiger parts worth anyway.
>
> Bob
> Robert L. Palmer
> Dept. of AMES, Univ. of Calif., San Diego
> rpalmer@ames.ucsd.edu
> rpalmer@cts.com
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