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Circuit breaker short

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Joined: Mon Feb 26, 2007 10:50 pm
Bikes: 1955 FL
1973 FLH
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Circuit breaker short


Post by 1955fle » Mon Jan 19, 2009 6:56 pm

Author: 1955fle

I have a very strange problem. Maybe someone can help. I have a short in my circuit breaker that shows continuity when the points are together or apart. Some how the circuit breaker is shorting to ground. I have traced all of the wires that touch any wire that touch the black wire from the circuit breaker and all look fine with nothing touching ground. When the circuit breaker is apart the wire terminal is separate from the breaker base.
The bike was rewired about 5 years ago by me. I followed the standard wiring diagram from the manual. This is driving me crazy. Has anyone run into this kind of problem?

Post by 1955fle

I should have mentioned the bike is a stock 1955 FL with a 6v system and manual advance. All of the parts are original except for the points they are new and the wiring that was replaced 5 years ago.

Post by 51hog

Mine did the same thing.
Remove the breaker cover and see if the plug on the wire that comes from the points could be possibly contacting anything that it shouldn't be.
Also, check for any missing insulation where the wire goes up through the bottom of the breaker.
Mine also had a 'wire hook' that hooked into the chafe shield that goes through the bottom of the breaker. If yours has it, check to be sure that the hook has not penetrated the insulation on the wire. You can do all that by checking the wire with an ohm meter. Remove both ends of the wire from where they attach, and connect one lead of the meter to the wire and the other lead to any ground point on the bike. If you show anything on the meter, then the wire is shorted.
If it is not in that wire, then check the insulator at the points.

Post by 1955fle

Thanks Dale. I have replaced the wire going from the breaker to the coil. When I remove the top of the breaker and check it with an ohm meter it will show when the points are open and also when they are closed. The only time that there is always a closed circuit is when I connect the wire that goes to the coil. Then it does not matter wether the points are open or closed. I get the same closed circuit reading on the meter. That's why this is driving me nuts. I have to be missing something very simple. -Carl

Post by gearbox

Check to see if your condenser is grounded out , remove the condenser wire from the point connection and see if you still have the same results( while you have the condenser disconnected , you can check it for being grounded by checking for continuity from the point connector wire and body of condenser or its strap). How old are your points, if you have a spare set (and you should have ) change them if condenser is OK . What condition is the terminal connector that goes through the breaker plate?

Post by 1955fle

I have tested this with the condenser out and I have the same result. The points are new. When I changed them is when I first noticed that there was a problem. First I thought that the insulator at the terminal connection was bad. But it is fine. When I remove the circuit breaker from the bike with the points and condenser all connected it is fine. When I connect the wire that goes to the coil is when the short happens. So there must be a short between the coil and the end of the circuit. This weekend I will go through each wire with an ohm meter to find where the circuit is grounding. There must be a broken wire that is touching something that it shouldn't.
This will be a very tedious process but I thing it is the only way to go. I will let you know what happens. -Carl

Post by kell
The only time that there is always a closed circuit is when I connect the wire that goes to the coil.
It sounds like that wire has shorted against the frame somewhere.
Isolate that wire by disconnecting it from the breaker (and the coil) and do a continuity test to ground.

1958 FLH
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1958 FLH
1947 EL
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Re: Circuit breaker short


Post by 1958 FLH » Tue Nov 03, 2009 2:53 am

I just happened to read your message. Hopefully you have already worked the problem out. I had a similar frustration. I changed my points and condenser and went to time it. I followed the directions in the official Harley Davidson service manual exactly. I hooked up the ohm meter and, like yourself, it didn't make any difference if the points were open or closed. It was very baffling. Eventually I realized that the manual omitted one very important step. That is, "turn on the ignition." Evidently, when the ignition is in the off position it grounds out the system.

You mentioned that you thought the problem might be something simple. In my case it was.


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