[C320-list] No charging until engine is revved repeatedly

[Graeme Clark]

Bob

I dont have the same engine but for what it’s worth, my manual says that the PINK wire in the engine pod, is the alternator field exciter.
It cahnges colour on it’s journey from the pod to the alternator, and i think its  pink not purple but nevertheless may be a clue?
Its a pretty thjick wire and in the engine instrument pod connects to the irnition switch. So when you turn the key, the poeer flows to the alternator exciter coil.
This might exppain why it works on the bench because the engineer will be putting correct field voltage to the correct terminal.
Hope this helps

graeme 
1996, #366



> On 2 May 2019, at 01:44, Bob Hoyt <rehoyt at gmail.com> wrote:
> 
> I posted this problem two years ago without resolution and since then
> nobody seems to have the answer. I have a 1994 320 with a Perkins M30
> engine and Lucas Marine alternator 55 Amp.
> 
> When I start the engine there is no output from the tach or voltmeter
> unless I "goose" the engine up several times (after a minute or two of
> running) then that wakes up the alternator and it reliably puts out 14.2
> volts. The idling speed is 1050 rpm and the green charge light stays on
> until the alternator kicks in. The voltmeter usually reads 12 volts. I have
> four new golf batteries and they are topped off with a solar panel and MPPT
> controller.
> 
> This week I took the alternator off and took it to a marine alternator
> specialist who claimed everything tested normal on his testing workbench.
> He wanted me to be sure that the small brown wire that is the "exciter"
> registered at least 2 volts and it registered 12.9. I confirmed that this
> wire goes to the charge light in the engine panel and that is exactly where
> it is supposed to go according to the schematics. I can find no other
> problems and none of the marine electricians have a clue. There is a
> disconnected pink wire that leaves the engine panel and runs down as far as
> the voltage regulator of ? significance. It does appear that over time that
> I have to rev the engine at even higher rpms several times for the
> alternator to work. I would appreciate any thoughts.
> 
> Bob Hoyt
> Hull #58 Ikigai
> Pensacola, FL
> 
> -- 
> 
> *Robert (Bob) Hoyt MD FACP*
> 
> *CAPT (Ret) USN*
> 
> *Associate Clinical Professor, Department of Internal Medicine*
> 
> *Virginia Commonwealth University*
> 
> *Richmond, VA*
> 
> *---------------------------------------------------------------------------------------------*
> 
> *Adjunct Associate Professor, College of Allied Health Professions*
> 
> *University of Nebraska Medical Center*
> 
> *Omaha, NE*
> 
> *Diplomate, Clinical Informatics*
> 
> InformaticsEducation.org  <http://InformaticsEducation.org>
> rehoyt at gmail.com
> 
> robert.hoyt at unmc.edu <robert.hoyt at unmd.edu>
> 
> robert.hoyt at vcuhealth.org
> 
> Cell: 850-384-5235