Oil Pressure Gages Do Dead When Both engines Started

[AKBASSKING]

With only one enginge running (Stbd or Port) the oil pressure gage reads normal. As soon as I place the other engine in "run" both gages go to zero. Gages in cabin normal.

Cause? Bad ground?

 

[AKBASSKING]

Well did some troubleshooting over the past few days. When one ignition switch is on, no issues, but as soon as I turn on the other switch, both oil pressure gages zero out. I disconnected the hot leads and no change. Disconnected one of the ignition switches and it seem ok. So I disconnected the signal wire to each gage and the gages became dead.

So I disconnected the sending unit on the port engine. The oil pressure gage was showing 40psi! Flipped the other ignition switch, gage goes to zero. So I ran a jumper wire from the sending unit to the signal wire and had good indication on the gage and no affect when Iflipped the other switch. So I will be running wires to the bridge straight from the sending unit.

There is something major wrong with the boat wiring. The re-wire I did was right on but the wiring harness from below is all screwed up. I will eventually have to replace all of it.....but for now it is fixed.

 

[1956olds]

I hear you there i had trouble with mine too after rewireing new guages .Port would read on stbd and vs ,so i switched yellow wires from ig switches helped but now had other problems like both gas tanks wired togeather and backwards syncro .had to remove ign wire from starboard syncro to tach ,killed everything ,so removed port ign from tach to syncro,all is well now.Wierd thing is it was a new pre wired dash from searay so they screwed it up in 97 when it was built.