electrical question

[HT byten]

I bought a new depth finder last year that has a volt meter.
With nothing else on it reads 12.5v,
with the motor running it drops to about 11v,
add running lights and it drops to about 9.8v. Is this normal? Should the running motor lower the volts?
Also the depth finder makes the running lights flicker. thanks for your help.

[Valv]

Which motor do you have, seems to me it's not charging battery.

[Gissert]

The charging voltage coming from the motor's alternator should be about 14 volts or so after an engine start. The voltage regulator will control the voltage at a level to ensure that the battery is always charging when the motor is running.

You may have a fuse that is blown, there may be some type of fusible link that has opened, or your alternator may be inoperative. The voltage regulator could also be the problem, or associated wiring.

[Valv]

HT, watch out at the shop, the "alternator" or "rectifier" (whatever you want to call it) it's not cheap. Just ask them if they can test it, it takes 5 minutes, and if it's the problem....well, you have to go for it.

[HT byten]

thanks for the info. i guess i'll have to take into the shop!
its a 1987 140hp einrude.
thanks again,
pete