I have said it before and I will say it again. Check the ground
connections. Check Alt to engine engine to Air frame and airframe to
battery. Use the voltage drop method, not resistance.
Michelle

Dave wrote:

Hi people,

Our PA28 has developed a problem. The Low Voltage indicator keeps
coming on. The engineer has replaced the Voltage Regulator which didn't
solve the problem at all. Then he changed the Overvolt relay. I flew it
for 50 minutes with no problems and then the next time I took it up
(some days later) the light came on within 10 minutes of takeoff, then
7 more times in the 1 hour flight.

It comes on at seemingly random times and can be reset by recycling the
alternator switch. Sometimes it stays off for 10 minutes, sometimes
half an hour (which makes tracking down the problem even harder!)

Any ideas?

Dave