Thanks Ben,

That site also has some great trouble-shooting suggestions:
"Low Buss Voltage can be caused by several things. Worn Brushes on
the Alternator. Poor Grounding . Abnormal resistance in the output
wire . Resistance in the aircrafts Field Circuit . Heavy electrical
loads - battery discharged- pitot heat - landing lights- storm scope
etc. can quickly add up to a 50 amp load . Alligator clip a wire
onto the output terminal of the Alternator and compare output voltage
to the voltage on the buss . They should be within .1-.2 volts
difference . If you are getting more there could be a problem on the
output wire. The Voltage Regulator is typically not the culprit in Low
Buss voltage. The vast majority of the time a Voltage Regulator would
fail completely and totally and not weaken . "

The other thing that came to mind was the possibility of single
shorted cell in your battery.

Regards

"Ben Stedman" wrote in message news:1066371638.368769@prawn...
here is the schematic:
http://www.inter-av.com/WiringDiagram.htm

ben