Valero 60A 14v alternator wiring on MD22L

[AB1707]

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

[fdemei]

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.

[Nigel]

The wiring diagram for your boat should show you where it goes.

[AB1707]

Thank you gents, sadly no wiring  diagram

[Nigel]

Start a new thread: Bavaria 38 Ocean 1997: Wiring Diagram needed

[Lyra]

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.