Hi all
I have had to put this alternator back on as my 90a one is kaput.
When the 90A went on the man told me he'd left off a yellow wire that wasn't needed on it.
This yellow wire is now unattached. I don't know where it attaches. It is live - using a voltmeter it shows the battery voltage and appears to run back to the battery.
Possibly connected my Rev counter & Engine hrs aren't working since the 60A went back on.
Anyone know? Picture attached
Hi man,
if do you have the battery insolator ( to charge main and auxiliary battery), The yellow wire ,MUST be connected to the auxiliary battery ( + ) .If do you have only one battery is enough to be connected to the alternato output (+ ) , but it must be connected, otherwise the output voltage grows more the 30 volt.
The wiring diagram for your boat should show you where it goes.
Thank you gents, sadly no wiring diagram
Start a new thread: Bavaria 38 Ocean 1997: Wiring Diagram needed
I now see that I have the same wire unattached and it is as follows:
1. This wire is the battery voltage sensing which makes sure that the regulator regulates according to the actual battery voltage.
2. When I bought the boat, the alternator had a yellow "pigtail" wire coming out of the regulator (this is the black&white part at the bottom left f your picture) - this sensing wire was connected to it, so if you have one you should connect to this wire (see attached picture).
3. Several months ago the regulator died and I had it replaced. the new regulator does not have this wire and the guy who fixed it said it was not necessary. I can only assume that the regulator senses internally the battery voltage off the +B terminal - not the best practice because this is the voltage before the isolator , which I believe drops about 1 volt. I will have to check the details next week.