AC Ground to DC Negative Bus connection

[Rocco]

While installing a new battery charger I stumbled upon the fact that the AC GND and DC negative bus are not connected on my 97 MKII.  I was wondering if others have discovered a similar situation or know where the AC GND to DC Neg connection is located on their 34?  This connection should be made in only one location and there is no obvious jumper from the AC GND bus to DC Neg Bus in the electrical cabinet; I'm trying to detemrine if there is a fault in my electrical system or if this omission is common.

Thanks,
Rocco

[karista]

Roco
When I installed a Galvanic Isolator, I found that there was no AC ground connection to the AC GFCI outlet at the chart table, further the Catalina AC wiring DIAG is incomplete, as it should show the connection to the DC ground. The Galvanic Isolator requires a AC-DC ground setup. My boat, indeed did have the AC-DC ground connection, however I do not know where Catalina made this connection and the WD does not show it at all. I did run a AC ground wire to the AC GFCI outlet to correct this serious wiring mistake.

[rirvine]

Like karista found, my 1997 MKII had the AC and DC grounds connected together. After much searching, I found that this was via the water heater – removing the AC ground from the water heater removed the connection between AC and DC ground.  If never worked out if this was intentional by Catalina or just "happened" that way.  I never when through the process of working out which DC ground was involved in this connection.  When I added a Galvanic Isolated (not sure if that did any good), I also added a jumper between AC and DC grounds.

Ray

[Rocco]

Thanks for the replies.

Ray, where did you place the jumper in the electrical "cabinet" between the two buse bars, or from AC ground to engine block?

Thanks!
-Rocco

[rirvine]

Rocco:

I placed the jumper in the electrical "cabinet" - shortest run and easiest to get to.

Ray

[karista]

Ray
Have you found any improvements since installing the Galvanic isolator? I have not realized any improvements in reducing zinc wear/replacements. As I see it, this was a waste of money!

[rirvine]

Not that I can tell so far.  It did tell me that most of the time when I plug into the AC at a dock there is no AC ground connection.  The issue is with the 30A AC connection at the boat - twisting it back a forward a few times "wipes" the AC ground contacts clean and then I have an AC ground.

Ray