Thor Forums

[javelin]

It is a pain to troubleshoot when you have to travel back and forth to the storage yard….especially with bad weather etc. By the way full charge is 12.6+ volts on a wet cell batteries FYI.
Interesting u/s switch cycles correct the problem until you shut the engine off again. It should only take less than a minute after you start the engine for the BCC control system to sense 13.2 volts or higher charging on the chassis battery…..so if you waited 5 minutes is there any change on the coach battery charge voltage? Also after your u/s fix cycles, when the coach battery is charging OK does it stay charging OK if you just leave the engine running?
The BCC cct board has an electronic voltage comparator circuit(s) that senses the 13.2 volt level and above to close the interconnect relay and 12.6 volts and below to re-open the interconnect relay. I am curious what happens when you have your problem (engine running, coach batteries not charging but u/s is on) and you operate the interconnect relay manually using the emergency start switch near the driver seat. You should hear the interconnect relay operate with your manual control. Operate it several times manually, then retest you’re your coach battery voltage. It would be best if you could manually operate the interconnect relay and watch if your coach battery charge voltage changes at that time…….hard to do with one person.
Since your alternator should basically be hard wired directly to the chassis battery (from factory or after this BCC recall) you know it charges fine. The interconnect relay is the only thing between the coach and chassis battery cabling other than tight clean connections or bad set of contacts in the relay. I don’t think the latching relays should have any impact on the intermittent problem but note that the u/s must be in use for the BCC control board to work…….so perhaps cycling the u/s was just hitting the voltage comparators on the BCC cct board……effectively cycling the interconnect relay? You might have a Winter think project and Spring resolve job on this one. Just make sure your batteries are fully charged if you leave them in your coach over Winter.