How to test voltage regulator output?

pict1000

pict1000

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Jul 19, 2019
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ILENGINE said:
there appears to be a 20 amp fuse in that wire. If that fuse(small chance) is blow or corroded(larger chance and possibly melted fuse holder) will cause the issues that you are having with the charging system.

This bypass wire is just replacing the purple wire in the diagram. If you get the temporary wire connected and it then charges then we know that the problem is in the purple wire. And you can go ahead and use your temporary wire as the direct replacement for the purple wire.
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Deafening applause for you! You are a Titan! It was in fact that 20 amp fuse -- blown to smithereens. Replaced it and my battery charges at 14v with everything wired back to factory settings.

When I ran that temporary wire that you suggested, the battery charged as it should. Then I knew to I had to find that 20 amp fuse you saw in the wiring diagram. It was well hidden or I would have checked it first. Your suggestions were stellar and you saved the day. Thank you a trillion times over!!!
 
J

JNaughton

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ILENGINE said:
With the engine running full throttle connect the red lead to the B+ terminal of the regulator, and the black lead to the negative post of the battery. What is the voltage. Should read battery voltage. Now mow the red lead to the metal housing of the regulator while still keeping the black lead on the negative post what is the voltage. Any voltage over a about 1 volt indicated bad ground to the regulator and battery voltage would mean no regulator ground.

Just trying to make sure you are actually getting battery voltage to the regulator and not just creating a circuit that may not be there, and making sure the regulator is grounded.
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Score another win for yourself! I’d already tried two new regulators (1 Amazon, 1 OEM) and was getting -2v on the B+ to battery -.
This was first I saw about checking battery (neg) to regulator housing. Sure enough, it was showing 4v. Removed the bolt the regulator ground wire was under, cleaned them both up with some sandpaper and BOOM! Charging like a champ.
Thanks!
Jerry N
 
S

slomo

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pict1000 said:
It was in fact that 20 amp fuse -- blown to smithereens. Replaced it and my battery charges at 14v with everything wired back to factory settings.
Click to expand...
Now, figure out WHY it happened. You are not done yet.
 
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