Engine won't start

[Scott Shearer]

I agree Lee, I've taken ours apart and cleaned it twice. Very corroded both times.

[George L Smith]

So, it's been a while since I reported the final ( at least so far ) solution. Looks like both of my chassis batteries were toast. They are rated at 1050 cold cranking amps. Had them both bench tested, and they tested at 660 and 700 CCA at 12.7 volts. Don't know how old they were. No markings on the batteries. Big Boy seems fine. The button switch on the BCC switches the relay just fine.

I replaced them both, and have been monitoring the voltage for the last week or so. Voltage holding at 12.7 volts. And no problems cranking either the engine, or the generator. So far so good. Everything seems to be working.

Does anyone here think that I have only cured the symptoms, not the disease?

[Mike Shumack]

12.7 V is a fully charged battery. You should wait about an hour after shutting engine or leave headlights on for a couple of minutes to remove the "surface charge" before taking the voltage reading to be accurate.  Be sure to start the engine and measure alternator output too. If you're getting in 13.5V range at batteries with engine running then, I'd say all is good.  Good luck.

[Steve Huber Co-Admin]

George,
IMHO you've nailed the problem. If you are concerned about the Big Boy, randomly check the  voltage on its 2 large terminals. It should be the same if the coach batteries are ~13V. If not, the internal terminals may be corroded and need cleaning. I disassembled mine this year (~11 yrs of use) and found the internal parts to be pristine. If the O'ring is good, there should not be any moisture intrusion and resultant corrosion. If it does act up, using the Battery Boost switch can sometimes get it making contact again as it closes the contacts.
Steve