Battery Voltage

Honda Pan-European 1st generation (German design)

Re: Battery Voltage

Postby David W » 26 Dec 2014, 23:59

Bill might want to check his battery voltage before starting the engine because the bypass wire might be powering the field coil even with the ignition off.
David W wrote:So the problem has been isolated to the wiring and components between the black, two-pin connector for the alternator and the positive battery terminal....
I would think Bill or someone should soon verify the theory behind all this, as follows.

With the engine running, what is the voltage between the two points where the bypass wire connects onto the Pan wiring?
Now shut down the engine, pull the fuse in the bypass wire, restart the engine, remeasure the voltage between those same two points, and shut down the engine.
The voltage should go up, verifying that there is an undesirable "voltage drop" or "voltage loss" from near the positive battery terminal over to near the black, two-pin connector for the alternator when there is no bypass. (Now replace the fuse in the bypass line, as it was originally.)
Here are the corresponding measurements from the other site:
BuddingGeezer on 11-19-2011 at 12:06 PM wrote: ... The line voltage loss to the black wire after [installing] this [bypass] was only 0.1 V rather than 5 volts....
I think the next step would be for Bill to decide if the above makes enough sense for Bill to do it himself, or to have an "electric factor" do it for him. (In the latter case, someone here could probably write up a summary of what is known, for Bill to take with him.)

As for tracing the wiring, my older Haynes manual, on pages 9-26 and 9-27, in the diagram called Honda ST1100 L, M, ....standard UK models shows a black wire going from regulator/rectifier to fuse D in the main fuse box, then to a red-with-black stripe wire to the ignition switch, then to a red wire going to the main 30 ampere fuse, and then to a black wire to the positive battery terminal.
Hopefully, the corrosion will be found at one of the two fuses because the ignition switch, even just its wiring, is harder to access than either fuse. For example, the fuse box can be detached from the black, plastic, rear fender to make it easier to inspect.
(They tell me that locating corrosion is easier using this "voltage drop" method than it is to try to measure such a small "resistance" with a standard meter.)
'Tis not its looks, but how it cooks.
And I've found that most liter size Pans, when warmed up, cook well.
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David W
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Make: Honda
Model: ST1100M/P ST1100AR/S
Year: 1991/1993, 1994/1995
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