Electrical Snafu ? ? ?

[R C Cola]

Lights dim and brighten about every 1/2 second at idle. Had electric checked on truck, all O K . Removed voltage regulator and tested, O K . Removed alternator and tested on bench machine, O K . Voltage at battery with truck running is 16. 8 to 17v . Question: Is it possible for a properly functioning voltage regulator to allow that much voltage to get to the battery. The battery is showing signs of overcharging but no damage yet I am aware of. Question:

Could a malfunction in another area cause excess voltage to get past the regulator. ? At a loss on thiis ? R C

 

[Philip]

A battery with low internal resistance can let a charging system overcharge.



A charging sytem is basicaly controled by the resistance it sees in a battery. Shorted plates/broken plates can let a charging system think the batter is low on charge. Then a overcharge condition can occure.

 

[R C Cola]

Batt Low Resistance ? ?

This is intrigueing. The Batt tested good, could have a low resistance. Is there a way I can test that out ? If not can it be tested at a shop ? Hate to replace a year old batt. without knowing for sure. Worth checking. RC

 

[Philip]

There is no way to realy test for resistance that I know of.



I had a battery in a 15,000 forklift not to long ago. It would test good on a load tester. The charging system was putting out 13. 9 volts with only 15 amp charge rate. I droped a new battery into it and the charge rate came up to 14. 6 volts and 30 amp charge rate. The complaint on the forklift was the battery was going dead if you were doing stop and shut off style of driving for very long. I haven't had a complaint on it sence the new battery.

 

[R C Cola]

Battery test !

Did another test and NAPA replaced the battery free under warr. Found 2 grounds in bad ahape corroded and rusty, repaired. Now charging properly at 14. 7v and all works fine. Thanks guys... . RC Oo.