Witchboard
Well-Known Member
Is this indicative of a bade voltage regulator?
Bad VR?
- Thread starter Witchboard
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Could be, can also be a short in the wiring or alternator. Do you get any charging with the regulator unplugged? What alternator and regulator are running, and did you make any repairs or changes about the time this started?
I don't like to see it charging 15 volts unless after cranking it a bit to get it started after sitting a week or two and then it will charge that high. There have been many threads about overcharging lately. Usually it is caused by voltage drop between the alternator voltage sensing wire and the battery which goes through a handful of connectors and the bulkhead connector. The resistance in each 50 year old connector can add up to too much, the alternator senses low voltage and the need to charge. Also many newly made regulators will overcharge. They aren't made like they were originally.
Here's a couple pages of threads titles with the word "overcharging" in the title. I would bet most have the same information posted about the subject.
www.forabodiesonly.com
Search results for query: overcharging
www.forabodiesonly.com
Witchboard
Well-Known Member
None that I've made, but this car has been modified from stock. I'll takes pics of the alternator and the voltage regular and try pulling the connection to the regulator and see what happens.
Pics of the regulator and alternator. I'll head back out after it stops raining and disconnect the VR. Is there a preferred cable to remove or just pull them both?
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Witchboard
Well-Known Member
Thanks, I'll check them out.Here's a couple pages of threads titles with the word "overcharging" in the title. I would bet most have the same information posted about the subject.
Search results for query: overcharging
Mattax
Just the facts, ma'am
Not really.
at .02 seconds it sounds like the engine idling and we see the battery discharging while the voltage at the fusebox is under 13. (The fusebox voltage is probably indicative of the voltage at the main junction.)
at .03 there's about 15 amps going to the battery and voltage at the fuse box is only 13.6 V
With increased rpm, voltage basically flattens out between 14.6 and 14.9 and battery charging goes to a bit over 20 amps.
So
a. The regulator is more or less controlling the voltage as it should, even as rpms go pretty high.
b. The battery is pretty depleted. It's either at the end of its life, or has been providing power and not getting recharged. (Or both).
c. The question is why isn't the alternator supplying the power at idle rpm?
A bunch of possibilities there. One possibility is a blown diode or open winding leaving the alternator down 1/3 of its capacity.
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