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Electrical question

23K views 278 replies 30 participants last post by  kd5cqt 
#1 ·
So was browsing through and saw where Chasarms was describing a draw test, and referred back to Schmidty's description of the test via Dave. In Schmidty's version, the maxi-fuse is removed prior to performing the test - what does this accomplish? I would think that would break the flow to all circuits, and that the test would always return a negative test (no draw). On my bike, when I did the test with the maxi-fuse installed, I saw a flow of 100 mA, but with the maxi-fuse removed I had 0 mA. What is this telling me?

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#2 ·
Actually, if you read the same post I did, it explains a procedure where you remove the negative battery cable, pull the maxi-fuse, put a milliammeter in line with the battery, then reinstall the fuse...

With the ignition off, the meter should read any parasitic draw in the bike...


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#3 ·
I missed the "re-install the fuse" part. I still am missing why removing and re-installing the fuse is part of the test.

It may be that the purpose of your life is to serve as a warning to others.
 
#4 ·
So if I have done the test correctly, my parasitic draw is 106 mA. Testing across each fuse with a mV setting, all fuses read zero. So if I have an issue, are the indications that it is an internal short to the battery, or possibly a worn battery cable?

This is what I get for being curious....

It may be that the purpose of your life is to serve as a warning to others.
 
#8 ·
Lol, I like your thinking.

I ask because I always distrust my own ability with diagnosing electrical issues, and detest trying to fix them, but am trying to get better about them. I am one of those guys that will make any electrical repair with a butt splice and electrical tape.

It may be that the purpose of your life is to serve as a warning to others.
 
#11 ·
#9 ·
Mason, given a DAS (Dead ASS Short), you'd have many amps and fried wires or blown fuse. A resistive short could be a few ma upwards from several hundred ma to a few amps...again, amps across the wires is going to produce some heat and you're going to probably melt the insulation. Internal short on the battery will show up as decreased potential across the posts because of internal voltage drop. I missed something here...what is the original problem you are hunting?
 
#10 ·
I had a loose terminal connector that slagged the post. Figured since I was swapping batteries anyway it was a good time to test my understanding of the test method and results interpretation. No real problem per se.

It may be that the purpose of your life is to serve as a warning to others.
 
#14 ·
The ratchet crimper is a great idea....at home, I prefer to solder all connections. And of course heat shrink tubing is one of electrical mankind's great inventions.
 
#18 ·
Which reminds me to order up some marine grade heat shrink.

Marine grade has a heat activated adhesive to resist water, oil, gas from penetrating the heat shrink seal.

 
#15 ·
So other than arcing due to a loose connection, what else might melt a battery terminal and kill a battery without blowing fuses or melting wiring?

It may be that the purpose of your life is to serve as a warning to others.
 
#16 ·
I don't think anything would.

If you had a solid connection to the battery, any amperage high enough to melt a battery terminal would blow the main fuse.
 
#19 ·
So was browsing through and saw where Chasarms was describing a draw test, and referred back to Schmidty's description of the test via Dave. In Schmidty's version, the maxi-fuse is removed prior to performing the test - what does this accomplish? I would think that would break the flow to all circuits, and that the test would always return a negative test (no draw). On my bike, when I did the test with the maxi-fuse installed, I saw a flow of 100 mA, but with the maxi-fuse removed I had 0 mA. What is this telling me?

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Always remove the maxi-fuse before disconnecting and re-connecting battery cables. Prevents arching and sparking !
Also when testing draw at the negative battery post allow some time for the electrical system to stabilize or the ma reading will be high. 106ma is high for a static draw test, should be about half that.
 
#20 ·
That makes more better sense - safety.

So if all the fuses pass the mV check, where would you begin looking for the draw?

It may be that the purpose of your life is to serve as a warning to others.
 
#23 ·
So if I were to say that the starter has had a hesitation for the last year or so (starts to turn, stalls almost like a dead battery, then fires up). Would you normally suspect the solenoid going bad? Especially if the draw ends up being in the starting circuit?

It may be that the purpose of your life is to serve as a warning to others.
 
#24 ·
Okay. Removing the fuse labeled "battery" drops the draw to 8.8 mA. So if I understand correctly, that leg leads back to the 40 amp fuse, which leads back to the starter. Am I getting warm?

It may be that the purpose of your life is to serve as a warning to others.
 
#26 ·
Just wagging here because only prints I have are for touring scoots, but the line going from the "battery" fuse also goes to the maxi fuse and also to the voltage regulator. From the maxi fuse, you go to main power at starter. Something else to occupy your spare time is the line goes also to the ignition switch.
 
#28 ·
The steady-state draw from the battery while the bike is off depends on the accessories you have installed...like radio, amp, whether you have a TSSM and siren, etc...but 106 mA seems high.

There is a table in the Electrical Diagnostics Manual that shows the standby draw of factory equipment...

The reason the procedure said 'remove the maxi-fuse, install meter, reinstall fuse' is likely for safety...if your ammeter leads touch he wrong thing before they're anchored, you blow the meter fuse, etc. Just standard procedure...



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#31 ·
No accessories to speak of, and no alarm, so TSM only. The starter has 120,000 miles of starts and stops, as does the coil, which is why I was leaning that direction.

It may be that the purpose of your life is to serve as a warning to others.
 
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