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View Full Version : Battery Cutoff Switch, would this work?



apr67
11-02-2003, 09:22 AM
So, I'm trying to do this with a one pole switch, because my experience with the battery cutoff switches has me spooked.

Here's my idea.

Put the cutoff switch in the positive battery cable, before anything else branches off.

Then run a line from the alternator output to ground with some sort of load on it.

That way, when I cut the battery, The alt still has a load to deliver, and it doesn't lose its little mind. I'm thiking of a light or fan as the load.

Is this crazy? In the past I have just run the output from the alt back to the battery (unswtiched) to continue the load.

Joe Craven
11-02-2003, 09:01 PM
On one side of your single pole switch, connect the battery + and the alternator output. On the other side of the switch, connect the power to the rest of the car including the starter. You can also connect this side to the field side of your alternator if it is multi wire. You can connect it to the other side too.

In this way, power is switched off to the car and motor will die. The alternator will continue to charge the battery until it finally spins down.

#37 ITB

Hey, I just bought an ITA car too!

The Sleeper
11-28-2003, 03:46 AM
There is a kill switch that has a connector in it for the alt to be run to that does exactly what you are trying to do. I can`t remember which one at this moment I had it on my GT2 Z I`ll try to locate it for you and let you know.

jc836
11-28-2003, 10:21 AM
May I suggest that you buy the Longacre 2-pole switch. It has the large battery pair and a smaller pair of terminals to disconnect either the alternator or the ignition main feed (50 AMP in a CRX). Why you ask-because it works. The Longacre switch sells for under $30 and is rated to handle the loads.
The way many cars are set up you want to break the main battery feed to the input of the MAIN fuse panel. In addition the trick we use is to kill the Ignition circuit since it supplies power to the Alternator FIELD windings. Honda cars will shut down doing it this way - but will not if wired in a more tortured fashion.
For other brands of cars, I urge you to use their specific wiring diagrams to determine the correct approach. I do have pictures of my car's setup; just e-mail for them.

------------------
Grandpa's toys-modded suspensions and a few other tweaks
'89 CRX Si-SCCA ITA #99
'99 Prelude=a sweet song
'03 Dodge Dakota Club Cab V8-Patriot Blue gonna tow

apr67
11-28-2003, 11:53 AM
Here's my take on this, and what I did (on a Miata).

I cut the battery's ground, and cut the positive feed to the main ignition circuit. Cutting the ground elimiates the battery, and cutting the ignition stops the engine. So when the alt stops spinning, their is no power.

To properly use the alternator cutoff method you have to have a switch that cuts the positive battery feed (i.e. in the battery cable as the rule calls for), and connects the alternator output to a grounded resistor.

I belive this would be a 'normally closed' swtich (contact) of 50 amps for the battery and a 'normally open' contact of 15 amps or so for the alt.


Alan