Alternator query

[Little yogi]

HI
I have a Vetus VH4.80 engine with Vetus heavy duty alternator 105 amp, since the start of the season every time I start the the engine from cold the tachometer and volt meter not work, until I rev the engine just passed 3000 rpm then everything works fine , if I leave the boat and come back a few hours or a day latter and start her up the Tachometer and volt meter work straight away without revving the engine, but if leave the boat for a week or so , then the same thing I have to rev her up to get the Tachometer and volt meter to work.

Someone said its normal as the alternator has to be ( excited ) apparently some alternators are self exciters not sure what Vetus alternators are , I bought the boat last year I not remember having to rev the engine to get the Taco and volt meter to work, the belt and batteries are new as they were replaced as part of the service, I had a multi on the alternator and get 12.4 with engine off and about 14.1 with engine running.

Hopefully someone on hear knows about alternators and get advise me

Thanks

 

[rafiki_]

HI
I have a Vetus VH4.80 engine with Vetus heavy duty alternator 105 amp, since the start of the season every time I start the the engine from cold the tachometer and volt meter not work, until I rev the engine just passed 3000 rpm then everything works fine , if I leave the boat and come back a few hours or a day latter and start her up the Tachometer and volt meter work straight away without revving the engine, but if leave the boat for a week or so , then the same thing I have to rev her up to get the Tachometer and volt meter to work.

Someone said its normal as the alternator has to be ( excited ) apparently some alternators are self exciters not sure what Vetus alternators are , I bought the boat last year I not remember having to rev the engine to get the Taco and volt meter to work, the belt and batteries are new as they were replaced as part of the service, I had a multi on the alternator and get 12.4 with engine off and about 14.1 with engine running.

Hopefully someone on hear knows about alternators and get advise me

Thanks

Sounds like the regulator on the alternator needs attention. Best find a commercial vehicle electrical repair business and try them?

 

[PaulRainbow]

HI
I have a Vetus VH4.80 engine with Vetus heavy duty alternator 105 amp, since the start of the season every time I start the the engine from cold the tachometer and volt meter not work, until I rev the engine just passed 3000 rpm then everything works fine , if I leave the boat and come back a few hours or a day latter and start her up the Tachometer and volt meter work straight away without revving the engine, but if leave the boat for a week or so , then the same thing I have to rev her up to get the Tachometer and volt meter to work.

Someone said its normal as the alternator has to be ( excited ) apparently some alternators are self exciters not sure what Vetus alternators are , I bought the boat last year I not remember having to rev the engine to get the Taco and volt meter to work, the belt and batteries are new as they were replaced as part of the service, I had a multi on the alternator and get 12.4 with engine off and about 14.1 with engine running.

Hopefully someone on hear knows about alternators and get advise me

Thanks

You can try a brighter warning lamp, or add a resister in parallel.

See here for some details, but don't read too far