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Westerbeke 40 electrical issues

3K views 12 replies 4 participants last post by  thevdeub 
#1 ·
I managed to shutdown all my instrumentation, likely by shorten the "buzzer" warning device. It seems to be connected to the "alternator suppression kit" and the alternator is not outputting anymore, on top of all panel having no juice.
At that point, my best guess is to replace all sensors switch (oil pressure, temperature). I could not find any breaker of any sort that could explain it. My boat is a Tartan37 from 78 and the engine wiring seems to be that old.
Anyone with a best guess where to look for ? Could I try to bypass all those switches with a 12v jumper on the positive of one of the gauge ? Afaik I can tell the ground is still good, there is just no volts on the plus of the gauges.
 
#3 ·
I can't find any fuse on this engine, and there is no solenoid, afaik, all get turned on when I press the ignition switch.
Attaching the diagram.
Are the 2 #16 green lines the ' excitation lines' of the alternator ? I am not sure what I should read there. They seemed both connected to the ground through this suppression kit (32) but at the same time they feed all my panel. And I used to read
12v on one of them...
 
#4 ·
Digging.

In the manual:
"Once the engine is running, fuel pressure developed in the low pressure side of the fuel injection pump operates a fuel pressure switch. Voltage is then applied to the alarmm system , to the alternator for excitation and for all instruments."

Looks like this one somehow is not working anymore.
Does that picture looks like a fuel pressure switch ?

But I have 0V both side. For it to work , should I not have at least 12v on one side ?
 

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#6 ·
I'm not sure what problem symptoms you are experiencing... so I'll start slow;
Do you have a charged battery aboard? If no, get one.
If yes, is it connected to the off-1-1&2-2 switch? If no, tell us to what it is connected.
Has the wiring harness been modified? If no, you have two trailer plug connectors that should be replaced with terminal strips.
If yes, you'll need to give us some details, or better yet an accurate schematic.
If the wiring is original (even if the trailer plugs have been removed), turn the off-1-1&2-2 switch to the 1&2 position. Test for +12V on the Purple wire at the back of the ignition switch.

I maintain an accurate schematic for my boat's primary electrical system. The boat is powered by a Universal M25. The sschematic looks something like this;
 
#7 ·
Well... I can start the engine, then my ignition switch is working and I have 12v at the alternator controller. Which feed into a second unit next to my ignition main cable... And there, nothing any more.

Do you see where I removed the line. Under that one i have 12v. And next to those 2, ;the 2 bigger ones are connnected to the switch that start the engine, then, they work...
 

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#8 ·
I have a T37 '77 w/ a W40 as well. I had a very similar problem a year or so ago. I clipped all connectors at panel, cut back wire till I saw good copper and put on new terminals. I also cleaned all the spades on the instruments. I also did the same on the alternator, and every where else on the starboard side I could get to. problem solved!

Also when my alternator went out last season, the panel would intermittently work.

Have the alternator bench tested, after trying the above. Also there is a OEM alternator on eBay that is about $90 bucks... although it cost me another 50 to ship to the carribean.

Hope that helps,

Oh, and the manual has a very good wiring diagram... although not in color the wire colors are indicated, as well as the thickness via varying 'bold' fonts.
 
#9 ·
Everything is grounded on the panel. I supposed all the positive should be 'open' instead then. I must have a short somewhere while fooling around. What bugs me is that the alternator is not kicking anymore, which seems really related to this "pressure switch" initial sequence.
 
#10 ·
Problem solved.
We do actually have breakers on those engines. The 2 round things in a previous picture are actually relay, that are not on the diagram, and have tiny reset buttons on the side. By shortening the alarm I likely triggered them. Pressing them solved this issue. Well, I learned something.
 
#12 ·
Great! Thanks for the follow up!!

Now that you've solved the riddle, I suggest that you create, and maintain, an accurate, as installed, diagram of how your system is configured.
 
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