Burstner 747 - Battery Warning Light On

[Guest Jonathan Revell]

The battery low-charge warning light is falshing. There is no 12 volt supply in the living area. There is mains (230V AC) power to living area. Batteries are fully charged. Local dealer cannot help until 23rd May. Help and suggestions please!

[Guest Docted]

Jonathon if no supply but battery fully charged my first port of call would be the 12V masterswitch followed by the fusebox. good luck Docted

[Guest Jonathan Revell]

Thank you. We check all fueses - OK. Where is the 12V masterswtich?

[Guest Derek Uzzell]

I believe Docted is referring to the main 12V 'caravan electrics' ON/OFF switch (or button) that one would expect to find on the central control-panel. (I'm sure there must be such a switch on your Burstner - also that you are familiar with it.) Obviously, if that switch is not properly in the ON position (or has developed a fault) 12V appliances in the motorhome's living-area will be inoperative. I note that Hobby's User Manual says about the battery-charge condition indicator on its control-panel - "LED blinks red. The battery is empty or not switched on". There is also a section headed "Protection against total discharge" that advises "If the voltage of the caravan battery sinks below 10.5V, a relay shuts down all the equipment that uses voltage". Unfortunately, I've no idea if this has relevance to your 747 as I've no clue whether Burstner and Hobby employ similar 12V systems. There is sometimes a main fuse close to the leisure battery but, as you've got an indicator-light working, it seems probably that some current at least is reaching the control-panel. As your battery low-charge warning light is flashing, it's sensible to assume initially that the voltage being sensed by the control-panel's electronics is genuinely low. So the first thing to check is what voltage is actually coming from your leisure-batteries. I know you say they are fully charged but, if I were investigating this problem hands-on, (a) I probably wouldn't believe you and (b) even if I did, I'd still check. (Are you sure that all the cables at the leisure-battery end are firmly connected? Are the earth connections secure?) Assuming the batteries check out OK, I'd then want to confirm the voltage arriving at the control-panel (this would mean gaining access to the control-panel's rear, which you may be reluctant to attempt) and check whether the 12V ON/OFF switch is operating satisfactorily. After that, it would be a matter of trying to decipher the wiring and hoping to spot something obviously cock-eyed (like a loose connection). Not a great deal of help I'm afraid - usually this type of fault either has a basically simple cause that's easy to fix or there's a component failure that demands replacement of the part to rectify the problem. If your motorhome dealer is unable to help in the short-term, an auto-electrician could be your best bet.

[Guest jonathan revell]

Derek, Thanks for the detailed reposnse. We enjoyed a wee drive in the motorhome yesterday. This charged the battery (checked by the control panel and with a multi-meter). 230 AV definitely delivered to the vehicle. All panel switches / function work OK now and show battery re-charged. I beleive that this indicates that the problem lies with the rectifier. Re. the Burstner safety devices - yes, when the battery is low ( < 11v) power to 12v deveices switched-off. Alternative for long lay-ups is complete switch-off. Main problem for me disinterest from our local dealer (cannot look before 24th May)! Burstner - this is a bought-in component so nothing we can do to help! This for a vehicle less than 12 months old and costing a lot of money.