| Re: Flat battery today ...alternator? [message #370480 is a reply to message #370471] |
Sun, 11 September 2022 20:43   |
boybach
Messages: 566
Registered: December 2020
Location: Vancouver Island
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Senior Member |
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The alternator tested good but the battery failed the load test. Battery is 4 yrs old BTW. When I got back to the coach I put the battery on charge again and got it up to about 12.5 after about an hour or so.
After reinstalling the alternator and battery, the coach started right up. I ran the engine for about 10 mins then turned on the headlights and blower for about a minute then shut the engine down. I should mention I have a chassis battery cutoff switch that I switch off whenever the engine isn't needed. I shut it off after engine shutdown.
After about 1/2 hour, I switched the battery on again via the cutoff switch and tried starting the engine. No go.
I installed another known good battery and went for a test run, about 5 miles or so, Dash A/C and blower on max. Stopped and restarted several times and coach behaved normally.
When I first discovered the non-cranking issue, the battery, which had been performing normally had been disconnected via the cutoff switch for about a week prior - so no chance of a parasitic draw pulling it down. I guess it just gave up suddenly?
Anyway, thinking a new battery is in the cards.
One thing I didn't understand. When I put the meter on the center tap of the isolator I got about 15+ volts or so and also when I put the meter on the house battery side of the solenoid I got over 14v too but when I metered the solenoid tap on the chassis side, the most I saw was 11+v and this was with the fully charged known-to-be-good battery. Is that normal if the chassis battery is fully charged?
Larry
Larry - Victoria BC -
1977 ex-Palm Beach "Ol' Leaky" 40,000 miles, PO said everything working but forgot the word NOT. Atwood helium fridge, water heater & furnace. SS exhaust system, Onan, Iota Converter, R134A, New fuel lines & heat exchange hoses
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