Charging wire from alternator

[Stu Jackson]

Perhaps the DP negative is wired to the bank somewhere, or a PO ran a separate ground.   Good thing to know, but not a deal breaker for now.  Trace it down when you get the time.

The banks' negatives should go nowhere near the DP.  OEM is #4AWG, unless a PO "improved" it.

You're right, the manual doesn't show this.  Least I haven't been able to find it in 23 years. 

[Ron Hill]

GWP : If you remove the main electrical panel on your 1988 C34; you'll find a negative DC buss bar at the inside top of that panel look at page 4.2.2 (D.C. System Wiring Diagram) of your owners manual.
 
I even ran another #10 neg. wire from the batteries direct to that buss bar to insure a good ground!!

A few thoughts

[KWKloeber]

Code Select Expand

This has me bumfuzzled. I checked the manual wiring diagram and it doesn't show another groung going anywhere else? What's going on here?  Thanks again

This post sorta explains it.
https://c34.org/bbs/index.php/topic,10604.msg82248.html#msg82248

as Stu noted the owners manual doesn't show the neg connection to the DP.  The panel diagram/schematic is incomplete.   The negative is (sorta) on the next page in the manualbut it's wrong.  See attached.

The panel diagram shows a "negative buss," which isn't at all a buss bar -- and is a combination positive/negative terminal strip.  See the annotations I added to that page, and the #10 gauge from the battery negative that the diagram did not include (I had no idea which screw it's on and anyway it probably varied by which day of the week the boat was wired.)

However the diagram on the next page (#4.2.4, excerpted out and stuck in the upper right corner) DOES show (incorrectly) the #10 negative wire to the DP.  OBVIOUSLY, a black negative wire or cable DOES NOT connect from the "ground terminal" to a positive battery cable as 4.2.4 depicts.

It's just how boat manufacturers typically haven't sweated the details about "boat electrical" -- not very unusual at all.

PS: #4.2.4 shows the neg cable on the "engine block" which typically is incorrect -- it's on a bell housing bolt, which isn't good -- it should be moved to a starter bolt.
   

[Stu Jackson]

Good points, Ken.

I found my hard-copy manual was wrong on the basic A.C. wiring.  Seems later diagrams corrected the error.

[KWKloeber]

Stu
When I D/L the pic it comes up too blurry to read?

[Ron Hill]

Guys : When I added a battery monitor and was mounting every thing to its negative shunt - I added a #10 negative wire that went under the flooring and connected into the negative terminal (Buss Barr as I call it!!) strip.  Did that so, I had a better/added ground from what the factory did!!   

A thought

[Stu Jackson]

Stu
When I D/L the pic it comes up too blurry to read?

Ken, thanks, I added a better copy.  The incorrect part was the OEM A.C. wiring.  I also added my Inverter/Charger to the diagram on the left side.