Electrical Puzzle
#1
Electrical Puzzle
I was reading another thread about a member trying to figure out where his electrical drain was. It was suggested to put a volt meter between the frame and negative cable to see if there was a draw with the switch off.
I tried it with a digital meter and I got 0.6 volts with the meter set on 20 volts. So I unhooked the regulator and it dropped in half. I then disconnected the starter motor and it dropped some more. With the battery completely disconnected I put the meter on the regulator and to ground and I got 0.24 volts! How is this possible?
I put the meter on my other shovel that didn't even have a battery in it and the regulator showed 0.1 volt. Are the magnets in the alternator enough to create some voltage even with the battery out? The same with the starter motor?
Both bikes have the 82 style alternator and regulator.
I used to just put a bulb in series to see if there was a drain not a meter. The bulb doesn't light.
I tried it with a digital meter and I got 0.6 volts with the meter set on 20 volts. So I unhooked the regulator and it dropped in half. I then disconnected the starter motor and it dropped some more. With the battery completely disconnected I put the meter on the regulator and to ground and I got 0.24 volts! How is this possible?
I put the meter on my other shovel that didn't even have a battery in it and the regulator showed 0.1 volt. Are the magnets in the alternator enough to create some voltage even with the battery out? The same with the starter motor?
Both bikes have the 82 style alternator and regulator.
I used to just put a bulb in series to see if there was a drain not a meter. The bulb doesn't light.
#2
#3
#4
the regulator will have some internal filter capacitors that will retain some voltage after the bike has been run, then turned off. When you put your meter in there to look for voltage, the meter itself will be drawing a very small amount of current out of those filter caps. I would bet that if you left the meter in circuit and came back a day or 2 later, the meter would have drained those regulator filter caps, and you'd then read 0 volts. A momentary probe with the meter would show you the voltage, but wouldn't draw much current, because as soon as you saw the reading, you then removed the meter leads.
A test light tester requires more current to light up it's light bulb...much more current than the filter caps could provide. The voltage was still there (as the meter proved) but there just wasn't enough "umph" (as in current...milliamps) to energize the test light bulb.
A test light tester requires more current to light up it's light bulb...much more current than the filter caps could provide. The voltage was still there (as the meter proved) but there just wasn't enough "umph" (as in current...milliamps) to energize the test light bulb.
Last edited by SeaZund; 01-21-2015 at 10:08 PM.
#5
#6
#7
Trending Topics
#8
#9
Join Date: Jan 2011
Location: Southeast Michigan 15 Minutes East Of Hell
Posts: 147,588
Received 47,745 Likes
on
18,544 Posts
Thread
Thread Starter
Forum
Replies
Last Post
bcolt
Primary/Transmission/Driveline/Clutch
4
11-09-2010 04:13 AM
94 Heritage
Ignition/Tuner/ECM/Fuel Injection
9
05-29-2007 10:41 AM