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  #1  
Old 11-16-2012, 04:34 PM
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Wonky Alternator?

Been having weird issues with battery and/or charging. I purchased a voltmeter that plugs into cigarette lighter and reads battery charge level and also state of charging system while running. It appears that my alternator is at times charging and at other times not charging the system - what would cause this? Diodes? Voltage regulator brushes are fine, belt is tight . . . . . I swapped out old battery with new group 49 battery - weird!

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Old 11-16-2012, 07:37 PM
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I have an analog Volt Meter and a Digital Volt Meter that plugs into the Lighter Socket.

It simply could be that the Meter is not making good contact inside of the socket or the Lighter Socket has some issues. You might check the Fuse that goes on that circuit.

Also I find that the Digital One that I have uses up about 1 Volt to run itself.

If you had a regular Volt/Ohm Meter you could check it against the plug in one.

Is there any sort of pattern as to when it is not charging like it always does not charge at idle speeds?
Also what other electrical stuff is running during the test?
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Old 11-17-2012, 12:01 AM
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Sweetie's car did similar.

Swapped regulator with know good. No change. Swapped alternator with known good. No change. Swapped back in other known-good regulator. No change.

The culprit? Crapped up newish "improved" glow relay, failing to release. The alternator isn't strong enough for continuous glowing.

YMMV.
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Old 11-17-2012, 02:55 PM
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Quote:
Originally Posted by BoiseBenz View Post
Sweetie's car did similar.

Swapped regulator with know good. No change. Swapped alternator with known good. No change. Swapped back in other known-good regulator. No change.

The culprit? Crapped up newish "improved" glow relay, failing to release. The alternator isn't strong enough for continuous glowing.

YMMV.
I have a quick glow system with a Ford Solenoid setup - I wonder if the solenoid could be occasionally engaging and failing to release?
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Old 11-18-2012, 01:03 PM
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Damn, alternator shows charging (did yesterday) via my onboard gauge and then last night, no charge on the drive home. Battery capacity was down too on start up so it appears that current is still being drawn off somewhere and that my alternator has some issues - wonder if its a diode issue?
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Old 11-21-2012, 12:53 PM
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Cheepie digital meters can be had from ebay at under $10. Ive used them for years and they just work.

Stepping on them if they are on the floor and smashing the leads into the meter is NOT recommended, they seldom work after that.

My alternator was intermittently putting out about 13.8. Drove over to a buddys place who has a really nice shop. There at ~2000rpm the 'output' measured ~12.6, indicating an alternator that wasnt putting out. The new unit put out about 14.2.
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Old 11-21-2012, 01:02 PM
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I've had a digital cigarette lighter voltmeter put out all kinds of funky readings. The voltmeter was bad. Don't take it for gospel.
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Old 11-23-2012, 04:42 PM
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Quote:
Originally Posted by kerry View Post
I've had a digital cigarette lighter voltmeter put out all kinds of funky readings. The voltmeter was bad. Don't take it for gospel.
Thanks! I am beginning to think that the solenoid is sticking and drawing off large amounts of current which makes the alternator appear to not be doing its job. I thnk it stuck last night and while driving, I hit the manual glow button a few times which seemed to deactivate the draw and then the volts measured were normal (13.6+) Weird!

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