Battery draining

[Gateside]

I have a new battery in my 1985 diesel Camper and I make sure that it is regularly charged, as I have had on going flat battery problems for a long time with my camper.

When I have the main headlights on for any period of time, eg up to 1 hour, it has drained the battery, to the point that the lights dim so much, that it is impossible to drive in the dark. Even the instruments such as the fuel gauge begin to not register, and gradually fade.

It is clearly not charging and the lights are draining the battery.

Is this liable to be a faulty alternator, or something more simple like it is just needing new alternator belts, or is it likely to be something else?

Any suggestions would be most welcome. Thanks.

[kevtherev]

Test the battery when the engine is running, use a multimeter set to Volts DC, put the red probe on the + ve batt terminal and the black probe on the chassis
reading should be around 13.5 to 14 Volts

this will determine if your alternator is charging the battery correctly

[Gateside]

Thanks, Any thoughts on what else it might be IF it's not the alternator?

[ninja.turtle007]

Check at the rear of the alternator and also at the battery. If the alternator giving the voltage Kev said but it is much lower at the battery then the power cable is at fault.