Battery Isolator switch
 

I have a 1930 Model A with 6 volt positive ground system.
I have to take the fuse off of the starter as soon as I shut the engine off or the battery will drain.
I want to install a battery isolator switch but can't find a good drawing of how it should be installed in this system.
I'm planning on installing the switch at the base of the drivers seat just behind the access to the battery.
I'd really appreciate some help with this.

Re: Battery Isolator switch
 

By the way I might not be calling this switch by the right name. Basically I want to install a switch that cuts power from battery to the car.

Re: Battery Isolator switch
 

I have one on my 29 Roadster that works Great!! I put it inside the engine compartment. Came with a mounting tabe. It cuts ALL power to the car and is out of site. Got it from Bert's in Denver. I am going down to my shop sometime this afternoon and can take a picture of it if you would like. It "breaks" the positive lead. I believe it uses one of the oil pan bolts to mount but will check it.

Re: Battery Isolator switch
 

Thank you Jim that would be great. I have a switch already but just not sure how to wire it in.

Re: Battery Isolator switch
 

In series with the battery. Either side of the battery will work, however, there has been a lot said of the benefits to putting it on the positive (ground) side. Really super simple as far as what connects where. The hard part is where to physically put the switch in a convenient place and the resulting routing of the rather heavy gauge wires to/from the switch. A lot has been written and discussed on that, you might get a lot of hits if you used the search function and sifted through the discussions. One thing is certain. Unless you have a show car for judging, it is certain that you DO need a battery shut-off switch.

Re: Battery Isolator switch
 

Hi Dave,
Best thing you could ever do for your old car. I even have one in my E Type as well as my 250SL Pagoda.
Jim has his in the engine bay, which means, you have to open the hood to turn off the ‘mains’
Unfortunately, this becomes a chore and eventually, you stop using the cut off switch.
Each to his own, but I have put mine in the cab, close to or under the seat. So this have become part if my start and shut down procedure, like in an airplane.
Master switch ON
Fuel ON
Ign ON
etc

So every time you walk away, you know the car is DEAD and will hopefully stay dead until you get back.

Re: Battery Isolator switch
 

Where you want to install the switch is a good place, easy to get to. Make sure the wires are heavy enough, no lighter than #1. It doesn't bother me which line the switch is in.

But, my main question is;;; why not find and fix the draw ?!
1. That off a battery lead
2. connect a test light or voltmeter between the lead end and battery terminal.
3. If there is a draw it will show on the meter or light the light
4. keep disconnecting things until the light goes out or the meter reads 0. Thats your draw. Fix it. [ Its probably the stop lights, dash light, or generator cut-out]

Re: Battery Isolator switch
 

Just tried uploading a couple of pictures but no luck. But the swith attaches to one of the bolts that hold the starter on (the one you actually see when you look at the started.. After you have attached the switch to the starter ( just ONE bolt) you cut the wire that goes from the Negative post of battery to the starter, strip the ends that are cut and attach them to the switch. Half hour job. Then when you put the car to bed for the night just snap the switch off and close the hood.

Re: Battery Isolator switch
 

Send me a PM if you have any trouble or questions

Re: Battery Isolator switch
 

Attachment 437363 think I got it

Re: Battery Isolator switch
 

I agree with Patrick, why not find and fix the problem.

Re: Battery Isolator switch
 

I would agree with you but when it comes to electrical I'm not the swiftest.
I replaced the cutout switch on the generator with a switch that has the diode in it but the drain got worse.


This was my Dad's car and he told me to always remove the fuse or the battery would go dead. I ignored that advice for awhile and had no trouble but then things changed.
I'm trying to bone up on my electrical skills but I still want to install the switch as a theft deterrent and Yes, I know that the average thief has no idea how to start or drive this vehicle.

Re: Battery Isolator switch
 

Thank you Jim. I really appreciate your efforts.
I'll keep everyone up to date on my progress.

Re: Battery Isolator switch
 

Hi Bill. Unfortunately I don't understand what you mean by "In Series".
I have a switch that has one long red lead and one long black lead.
Both are battery cable gauge.

Re: Battery Isolator switch
 

Color of the wire is not important. Where the positive side of the battery connects to the frame, unhook and set aside that cable, and place one of the wires from the switch To the battery where the cable was, and connect the other switch wire to the frame. Now the switch is in series. Figuring out where to mount the switch is totally up to you and your preference. The cable you removed and set aside, you can toss it or save it. It is not used with the switch.

Re: Battery Isolator switch
 

The color of the wire could be important. If it is a red wire, connected to the battery/starter it is probably sized for a 12 volt system and not a 6 volt system. Is the battery installed with a positive ground, as it should be? If the fuse is out and the battery still is draining down your car has a wiring problem or a bad battery. You should do the right thing and find the problem and fix it.

Re: Battery Isolator switch
 

Installed one using the opening in the motor mount behind the starter on my 28 Phaeton. Negative cable from starter to switch, another cable from switch to negative connection of battery. Rubber boots not shown were installed on switch contacts. Open hood to access not a big deal.
RollinRock
Gettysburg

Re: Battery Isolator switch
 

The battery should not be drained when not running. The disconnect switch can be a good safety device but the reason for the current drain should be found.

Marc

Re: Battery Isolator switch
 

Aquadave, if you have an alternator in place of a generator, you may have an internal leakage in the alternator and will discharge your battery in a few days. Best to pull the fuse mounted on the starter, or install a disconnect switch like you plan to do.

Re: Battery Isolator switch
 

Not seeing where you activate the switch on/off. Your third photo appears to come up thru your floorboard.