Battery constantly draining

[eric.schaefer]

1931 cabriolet was running great, now the battery goes dead in less than a day. I can charge the battery and drive it and then the next day it is completely dead. Won’t even run the horn or lights it’s so dead. I’m not sure how accurate the amp meter is but it does show 15 amp discharge when the key is off and the car is sitting. So something is pulling power when the car is just sitting there.

This is a negative ground 6 volt car. There is no fuse on the starter

Here is what I have checked.

-brake light and lights are not constantly on or stuck on.

- battery cables are not damaged or rusted. Good ground on the negative to the transmission.

-changed the coil out just because it was easy and I had another good coil.


Thanks for any help.

[midgetracer]

Probably the cutout stuck and trying to motor the generator.

[wmws]

Disconnect the wires coming out of the cutout. Put you amp meter across and see if there is any draw. If you don't have an amp meter just disconnect one wire at a time and see if it helps. You have a bad wire somewhere it is just a matter of finding it.

[Tom Wesenberg]

Originally Posted by midgetracer

Probably the cutout stuck and trying to motor the generator.

Yes, for sure. When you remove the wire from the cutout that goes to the terminal box, you should see a spark if the cutout is stuck closed. Most repro cutouts aren't worth the price of the scrap metal you could sell them for.


I've never had a problem with a good restored original cutout, and some don't even need to be restored.

[Jim Brierley]

Do as WMWS says, only you may need to use a voltmeter to detect any small drains. I had that problem a few years ago and it was my brake light switch, draining the battery so slowly the lights did not glow, but drained the battery in about a weeks time. Good luck!

[1crosscut]

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Disconnect one of the battery cables and put a test light between it and the battery post. If you have a power draw the light will come on. Start disconnecting wires until the light goes out. When it does you will know where the trouble is.

[CWPASADENA]

You say 6 volt NEGATIVE GROUND?


Are you running an alternator?


If so, a bad diode in the alternator can drain the battery.


If you are running a stock Model A generator, it should be POSITIVE ground in less it has been modified for a negative ground system.


Chris W.

[Brian in Wheeling]

Yes, cutout or alternator...depending on what your running. My 2 cents.
Brian W.

[1931 flamingo]

How old is the battery??


My 6V pos ground alt system will go dead also IF I forget to hit the "kill" switch .
Paul in CT

[Y-Blockhead]

A bad diode in the alternator will cause it to drain overnight. Oops, saw CW already mentioned this.

[eric.schaefer]

Battery is brand new, had to recharge it yesterday because it drained over night. I did what was mentioned and with the battery hooked up I disconnected the yellow wire with black marks on it that is connected to the cutout. It for sure sparked and has power there. When I left it off the cutout the ampmeter showed 0. When I connected it the ampmeter showed 15 discharged. With that being said what is the issue haha? Bad cutout?

[Jim Brierley]

More likely the generator.

[eric.schaefer]

Here is a picture I do not know if it’s a generator or alternator

[Bob C]

That's a generator. Not sure whats up with the cut out, where does the blue wire go?
Also looks like you have the wrong water inlet pipe.


Bob

[eric.schaefer]

Blue wire goes from the backside of the cutout and looks as if it grounds on the generator

[Bob C]

It is hooked to the generator output on the end of the wire you can see.
Is one end of the blue wire hooked to the generator output and the other
end to the cutout ARM ?



Bob

[Ed in Maine]

You might also check the wire inside the armoured cable from the ignition switch. The insulation can get brittle and break and ground out. Also, try disconnecting the connections to the head lights. Sometimes the fittings are worn and don't hold the wires properly to the head light shell and ground out. Look for shorts to ground inside the distributor, under the upper plate. Good luck, Ed

[barnstuf]

Another thought is that cutout is obviously a replacement cutout and may have a diode and not have points in it. If so current only goes one way in a diode and they require a positive ground when installed on a Model A.

On the other hand if the replacement cutout does have points, and the points stick closed,. usually just tapping the cutout body with a wrench creates enough vibration for the points to open

[Badpuppy]

Originally Posted by Ed in Maine

You might also check the wire inside the armoured cable from the ignition switch. The insulation can get brittle and break and ground out. Also, try disconnecting the connections to the head lights. Sometimes the fittings are worn and don't hold the wires properly to the head light shell and ground out. Look for shorts to ground inside the distributor, under the upper plate. Good luck, Ed

The wire inside the armor is usually grounded except when the points open. That part of the circuit is completely removed when the ignition switch is off - unless the switch is shorted through, which is possible.

[Tom Wesenberg]

The cutout should have an L bracket to connect to the generator post. No other wire should go to that side of the cutout. If it was my car I'd call Bert's and order a good restored original cutout with the mounting screws and L bracket.


At the same time, you should order the correct 1928-9 lower radiator outlet pipe. Your's is for 1930-1 radiators only.


Bert's 800-321-1931