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Old 05-17-2020, 07:58 AM   #1
shew01
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Default Need Help in Identifying Location of Short

My 1931 Victoria is 6 volt positive ground, and I recently replaced my repro ignition switch and cable with a rebuilt one from Dick Crabtree.

The previous owner installed a power cutoff on the positive side of the battery, and I normally leave the car plugged into a battery minder (https://smile.amazon.com/gp/product/...?ie=UTF8&psc=1). The previous owner gave me the battery minder when I purchased the car; so, this unit has been successful for a number of years.

If leave the power cutoff turned "off," the battery remains at 6 volts, as it should. If I leave the power cutoff turned "on," the battery will drop to about 1.5 volts in less than 24 hours, even with the battery minder plugged in.

I presume the issue is with the rebuilt ignition switch or the wiring in the junction box that I disturbed to replace it. I'm not sure where to look or how to test. I do have a multimeter, but I need direction for how to proceed.

Any help is appreciated.

Last edited by shew01; 05-17-2020 at 08:04 AM.
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Old 05-17-2020, 08:18 AM   #2
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Default Re: Need Help in Identifying Location of Short

Do you have the armored cable that screws into the distributor, looks like a big spring? A couple things to check if that is what you have, first and easy to check is where it screws into the distributor, it could be screwed in too far and may push the lower plate against the body, it just needs to be tight enough to make good contact with the spring loaded plunger. Also there is a regular insulated wire that runs up that spring like case and that can rub and make contact. The switch itself could have a break in the internal insulation that is leaking. I had an old original switch that actually got warm so I just got one at NAPA and use that since I don't plan on showing the car anymore. If you have a test meter you can start testing all these different places or just switch back to your old switch to see if that is the problem. I had a cable give me problems on the old rusty car so I just ran a wire directly from the switch to the lower plate and connected with a screw, looks bad but works with out that antithieft armored cable with the spring and copper plunger. ( you don't want to do that, haha)
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Old 05-17-2020, 08:29 AM   #3
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Default Re: Need Help in Identifying Location of Short

Do you have this book:

https://www.mafca.com/cart/index.php?productID=168

Look at the wiring diagrams and make sure you have the wires hooked up correctly.

You may have to open things up and take some pictures of how you have it all wired up, then post them here, for someone to help you spot the error.
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Old 05-17-2020, 08:29 AM   #4
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Default Re: Need Help in Identifying Location of Short

Turn your disconnect switch to on. Disconnect wires to head lights tail lights horn etc. one at a time. Then hook you multimeter in the line to see if it is drawing current. Or even while your disconnecting wires if you see a little spark that is the bad one.
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Old 05-17-2020, 08:37 AM   #5
Ed in Maine
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Default Re: Need Help in Identifying Location of Short

Last month I removed the instrument panel on my 31 Victoria and managed to create a short while putting in back in. In my case, the metallic covering on the dash lite wire had gotten up against one of the terminals of the ampere meter. I wrapped it with electrical tape in that area of the ampere meter terminal to solve the problem. Good luck, Ed
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Old 05-17-2020, 10:10 AM   #6
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Default Re: Need Help in Identifying Location of Short

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Quote:
Originally Posted by shew01 View Post
My 1931 Victoria is 6 volt positive ground, and I recently replaced my repro ignition switch and cable with a rebuilt one from Dick Crabtree.

The previous owner installed a power cutoff on the positive side of the battery, and I normally leave the car plugged into a battery minder (https://smile.amazon.com/gp/product/...?ie=UTF8&psc=1). The previous owner gave me the battery minder when I purchased the car; so, this unit has been successful for a number of years.

If leave the power cutoff turned "off," the battery remains at 6 volts, as it should. If I leave the power cutoff turned "on," the battery will drop to about 1.5 volts in less than 24 hours, even with the battery minder plugged in.

I presume the issue is with the rebuilt ignition switch or the wiring in the junction box that I disturbed to replace it. I'm not sure where to look or how to test. I do have a multimeter, but I need direction for how to proceed.

Any help is appreciated.
How old is Battery?Re-look at what you did to replace the items?
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Old 05-17-2020, 10:34 AM   #7
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Default Re: Need Help in Identifying Location of Short

Take a small 6V bulb and attach alligator clips on insulated wires about 6" long for each wire to the bulb on the end where it makes contact in a socket and the sides with solder. Would suggest you place heat shrink tubing around the connections on the bulb Attach the alligator clips across the terminals of the cutoff switch when in the "OFF" position. You will need the battery to be charged up. If there is a current draw, then the bulb will light up. Start disconnecting the wires to headlight, horn, tail lights etc. until you find the short.
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Old 05-17-2020, 11:24 AM   #8
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Default Re: Need Help in Identifying Location of Short

So you now have a draw when the master switch is on but the key switch is off ?

Just take our volt meter or test light, remove a battery lead that is easiest to get at. Connect the test light or meter between what you just disconnected. [ the ground battery terminal and its cable are the best, but any will do] The light will come on or the meter will show the draw. Disconnect 'stuff' until the light goes our or the meter shows no draw and thats your problem.
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Old 05-17-2020, 11:38 AM   #9
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Default Re: Need Help in Identifying Location of Short

If you would have a short you would have a hot spot or smoke. If your having a draw down I would check the generator cut out to see if it is sticking closed. Remove the fan belt and see if the generator motors.
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Old 05-17-2020, 12:15 PM   #10
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Default Re: Need Help in Identifying Location of Short

See attached article.

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File Type: pdf A hidden fault.pdf (127.6 KB, 71 views)
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Old 05-17-2020, 12:22 PM   #11
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Default Re: Need Help in Identifying Location of Short

If you are drawing that much current, then something is getting warm or even hot. Look for it. Usual suspects are: lights, including the brake light, generator trying to motor, short down stream of coil, Some little wire getting very hot. Good luck.
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Old 05-17-2020, 03:52 PM   #12
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Default Re: Need Help in Identifying Location of Short

Thanks for all the responses so far. I started with Tom Endy’s post first because I remembered the junction box studs being loose when I was working with the armored ignition cable earlier in the week. In an effort to make sure that the junction box studs are not shorting to the fit wall, I took it apart and put some sealant on the two heads that can short, and I added some thin gasket material over the heads before putting the junction box back together. I think I can cross this one off the list.


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Old 05-17-2020, 03:57 PM   #13
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Default Re: Need Help in Identifying Location of Short

Quote:
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If you are drawing that much current, then something is getting warm or even hot. Look for it. Usual suspects are: lights, including the brake light, generator trying to motor, short down stream of coil, Some little wire getting very hot. Good luck.

I started looking for something warm, and it turns out the coil is warm.

Here is something else odd. With the cutoff power “on,” and the ignition key “on,” I get 6 volts to the moving point arm when the points are open, as expected. However, under the same scenario, but with the ignition key “off,” I get still get .3 volts on the moving point arm.


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Old 05-17-2020, 04:02 PM   #14
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Default Re: Need Help in Identifying Location of Short

Here are some pictures.





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Old 05-17-2020, 04:40 PM   #15
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Default Re: Need Help in Identifying Location of Short

Attached are a couple of electrical trouble shooting articles that may be of help.

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File Type: pdf 2OC-Quick & easy.pdf (124.4 KB, 38 views)
File Type: pdf Roadside Electrical-pdf.pdf (418.0 KB, 37 views)
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Old 05-17-2020, 07:52 PM   #16
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Default Re: Need Help in Identifying Location of Short

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With the cutoff power “on,” and the ignition key “on,” I get 6 volts to the moving point arm when the points are open, as expected. However, under the same scenario, but with the ignition key “off,” I get still get .3 volts on the moving point arm.
Sounds to me as if you have something connected incorrectly or your switch is BO and leaking thru. With switch off there should be zero voltage at the points, if you car is wired correctly.

Do you have any accessories wired into the ignition switch?
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Old 05-17-2020, 07:55 PM   #17
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Default Re: Need Help in Identifying Location of Short

See if your ignition switch gets warm. The point arm must have zero volts when switch is off. I bet it is almost off. Bypass the switch with a jumper and see what you have. Sounds like you understand the circuit.
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Old 05-17-2020, 08:24 PM   #18
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See if your ignition switch gets warm. The point arm must have zero volts when switch is off. I bet it is almost off. Bypass the switch with a jumper and see what you have. Sounds like you understand the circuit.

I’ll need to check for warmness at the ignition switch tomorrow. If the armored cable is shorting at the distributor, would that cause the coil to get warm?


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Old 05-17-2020, 09:21 PM   #19
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I’ll need to check for warmness at the ignition switch tomorrow. If the armored cable is shorting at the distributor, would that cause the coil to get warm?


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When the switch is off there is no power thru the armored cable.
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Old 05-18-2020, 12:01 AM   #20
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Default Re: Need Help in Identifying Location of Short

You said this was a rebuilt original ignition switch, yes? If so, not to be rude, but are you aware that it needs to be pushed in to be off?
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