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'04 FXSTDI
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906 Posts
Discussion Starter · #1 ·
I have a friend's 98 Heritage on my lift. It appears to have a short that drains the battery with everything turned off.
How should I begin testing for a short in this situation?
the bike has recently undergone a BB build. The problem has appeared since the build.
I've looked and searched but cannot find any relevent posts.
Any help would be appreciated.
JimA
 

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Administrator
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11,287 Posts
Place an amp meter between the positive post of the battery and the battery cable. If you are correct, you will see a current draw with the bike in the off position. With the wiring diagram, find the breakers and disconnect them one at a time. When you disconnect one and the current drops out, you will know it is in that circuit. Using the wiring diagram see what is attached to that circuit and repete the above preceedure until you have isolated the cause.

Any questions feel free to PM me and I will give you my number to discuss it in greater detail.
 

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2005 Road King Classic
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1,632 Posts
Great advice Springer.

Start with removing any after market electrical items, then follow Springers advice!
 

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'04 FXSTDI
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906 Posts
Discussion Starter · #4 ·
Thanks Springer.
The bike doesn't have any aftermarket electrical items except for the upgraded ignition module.
Given that the problem appeared after the build, are there some items I should look at first?
Thanks a heap!
 

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Administrator
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11,287 Posts
Just start at the beginning and narrow it down. It's not hard, just methodically.
 

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2005 Road King Classic
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1,632 Posts
Start with the "upgraded ignition module" and then lights (brakes first) then anything with switches (handlebars, accessories, etc).

Good luck!
 

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'04 FXSTDI
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906 Posts
Discussion Starter · #7 ·
One more stupid question before I start this tomorrow.
By breakers, do you mean at the fuse box?
 

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Administrator
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Typically you'll have a Main breaker at 30 amps and then 3 15 amp breakers. They are self resetting breakers and not really fuses. I might depend on the year of the bike. It has been a while since I have worked on a stock wiring harness, but the theory applies no matter what. For example, a car has many fuses. You would do the same thing with the amp meter and then start pulling fuses until your current draw dropped out. Then you would check what fuse you pulled and then concentrate on that circuit.
 

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Administrator
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11,287 Posts
As mentioned, the ignition module might be a good place to start. If it was wired so that it was on all the time, that could easily be the cause. I have always attacked electrical problems methodically and it always leads to the problem. It cuts out the pot shot guess work, but sometimes that can be quicker if you guess right early on.
 

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'04 FXSTDI
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906 Posts
Discussion Starter · #10 ·
I'm all for the methodical approach. good way to narrow it down and eliminate possibilities. I figure even if I find a short , I'll keep going throughout the fuseblock checking all the circuits. It could be more than one.
JimA
 

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I'm Paid Up...
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1,732 Posts
Sounds like you have some excellent advise here. I work on equipment that has a 130 page wiring diagram, and this is exactly how you track these problems down.
 
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