HELP!!! Electrical problem

[wduprez]

I have a resored '31 It has developed a drain on the battery of 1 volt. If I disconnect the "hot " wire to the horn the short goes away. I checked continuity from the horn ground wire at the horn, to ground...no continutity(no short from the horn to the button. When I press the horn button, then I get continutiy. ANY IDEAS???????
tHANKS FOR YOUR REPLY!!!!!!!
Wayne Model A Ford Club of Long Island

[jrelliott]

Sounds like a short in the horn or frayed wiring to horn. Pull the ground wire from the horn, hot wire still connected and see if you still have the short. If you still have the short then it is in the horn or wiring to horn.

[Will N]

What about checking continuity from the hot terminal to ground without pressing the horn button?

[wduprez]

Originally Posted by Will N

What about checking continuity from the hot terminal to ground without pressing the horn button?

Hi Will, I disconnected the battery then did the test you suggested. Horn hot wire to ground.... No conductivity (short to ground)

[Tom Wesenberg]

jrelliot has it covered. Also use the amp function (always start with the highest setting on unknown value, then switch down to get a useful reading) and see how many amps, or milliamps it shows as a drain. Since you show only 1 volt, the drain will be very small. Make sure the brushes and brush holders are clean.

[wduprez]

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Originally Posted by jrelliott

Sounds like a short in the horn or frayed wiring to horn. Pull the ground wire from the horn, hot wire still connected and see if you still have the short. If you still have the short then it is in the horn or wiring to horn.

Hi, I did what you suggested, with the battery disconnected. No continuity. Reconnected the battery, still have the short.

[Will N]

This is a poser. If neither the hot side of the horn terminal nor the ground side has any continuity to ground when the wiring is disconnected, you've pretty well ruled out a short in the horn itself.

That leaves the hot wire coming to the horn. But you say when you disconnect it, the short goes away. It could be a slightly frayed wire that when you move it around is breaking contact to ground. But I think even a slightly frayed wire would show up with much more of a drain than 1 volt, right?

[wduprez]

I have run out of time today to further check the problem. I'll leave the battery disconnected for now. Thanks for your ideas !!!!!

[Mike V. Florida]

I'm sorry but what do you mean a "drain of 1 volt"?

No matter what if you remove the wire from the horn and your problem goes away then your problem is in the horn.

[Willie Krash]

I'm with Mike and Tom. I don't understand a 1V short.
A simple, very simple test is use bulb, current matters. One can take a VOM and attach to one pole of the battery and use the other lead on the top of the battery and read voltage.
A simple bulb test will indicate .250mils or less. time is the variable.
I once told a customer to hold my hand. I hooked a lead to one side of a battery. I held the other lead of the DVOM in my hand and asked the the customer (holding my hand) to touch the other pole of the battery. The meter read 12.6V.