Alternator

[saveloy 8]

I measured the voltage at the battery today. Since I can physically feel the engine holding back, once the anciliaries are on.

Battery voltage( engine off) - 12.45 V

Battery voltage(engine 2000 rpm) - 13.7 V

Battery voltage(2000 rpm,lights on) - 13 V

 

Strangely, the battery light on the dash isn't lit at all. Although my SPA gauge is giving me a low battery warning.

[Mikey S 29 1 Cars]

I measured the voltage at the battery today. Since I can physically feel the engine holding back, once the anciliaries are on.

Battery voltage( engine off) - 12.45 V

Battery voltage(engine 2000 rpm) - 13.7 V

Battery voltage(2000 rpm,lights on) - 13 V

 

Strangely, the battery light on the dash isn't lit at all. Although my SPA gauge is giving me a low battery warning.

 

from a healthy alternator you tend to get somewhere between 13.8 to 14.2 volts. i presume you took all your readings from the battery? if so, take them from the back of the alternator. this will give an more accurate voltage reading of what the alternator is throwing out. its quite common to loose half an volt or so due to current drop, corroded terminals etc at the battery.

 

with regards to your battery voltage. its sounds like its discharged. a healthy battery should read 12.7 volts, a 50% charged battery 12.6 and a discharged battery 12.5. so it maybe a battery fault. have you tried droptesting it?

 

hth

 

mike

[saveloy 8]

The wiring is sound. The battery voltage when I bought it was 12.6V. So all things point towards the alternator, surely?

[saveloy 8]

Alternator changed, but only a small change in output voltage. Just under 14 volts. Bastard!

The only thing I can think of now is a bad earth. I will check the battery to chassis and engine straps.

Unless there is something else?