battery gauge

[panthrow1]

my battery gauge (d-reg 1.3sr) used to sit half way between 1/4 and 1/2 (1/3), after fitting an amp (only a 250w kenny) it dropped a little bit but was o.k for 6 months. the battery then went flat, i recharged it and it went flat.
i took the alternater out and was going to change it with one from a f-reg sr, the connections were different though so i put it (original one) back in. the gauge then started reading in its original position.
untill a week ago when it went flat. i bought a new battery yesterday (sick of bump starting it by my self) and now the gauge only sits at a quater.
ive checked the belt and its not loose.
is it the alternater, or is the gauge just an irrelevant piece of sh**e?

[Doddy]

check the connection on the alternator for the gauge, black/blue wire, i think.

It should sit at about 1/2 when running, if all is well..

[Ste_Nova]

check the earth strap on the alt to engine and the engine to car
p.s. if the alt charging light doesn't work the battery won't charge

[Anonymous]

stick a voltmeter on the battery, then start the engine and take her to a couple fo grand so the alternator is spinnign well. if the voltmeter goes up then the alternator is working, if it doesnt then its not charging this could be a wiring fault or the alterntor itself.

Chip