I recently acquired a 1985 110 Station Wagon with V8 and LT95 4-speed. Recently started having a problem with keeping a charge on the battery (which looks new).
When driving during the day (i.e. lights off) the voltmeter on the dashboard pretty much consistently shows the needle in the middle, which I assume means it's charging at 12 - 13V.
But then daylight savings rolled around again and I had to drive at night. As soon as I turn the head-lights on the voltmeter needle drops down into the red. Speeding up to 60mph brings the needle up slightly above the red, but as soon as I slow down it drops back into the red. And then the last time I went to start it up the battery was pretty much dead. Jump started it and ran for a while (with lights off) and it seems fine again. But obviously I'm not keen on driving at night.
Alternator drive belt is new and looks tight.
What would cause the drop in voltage when I turn on the headlamps? Do I have a short somewhere? Or is the alternator simply not strong enough to keep up with the demands of the lights? Any other ideas?
Help much appreciated!
Cheers
Ian