intermitent tach lights

[hydra23]

Engine model J175EXEDB. After hitting a wave hard the following started to happened all my tach lights hot, no oil, check engine ect will come on for about 2 seconds and go off seems like the system check is constanly recycling like when you first turn the ignition. Engine runs fine, there is no overheating, oil tank is full, fuel is fresh. System charge shows a steady 14V at 1500/2000 anything above 3000 the gauge will read 12.5 to 13V. If I turn on the bilge pump or the bait well switch while running above 3000 rpm the rpm needle will move out of control. Im only running a GPS a fish finder and a marine radio, no new electrical items installed or removed.

Could that be a loose ground? a bad regulator/rectifier?

Regards,

Jose

 

[jtexas]

Re: intermitent tach lights

I would expect a solid state device like that to live through most any shock that doesn't break the boat apart, but a close visual inspection might reveal a problem. Look for obvious physical damage, make sure the mounting bolts are tight and wiring is still good.

The apparent relationship between the pumps, the tach, and the charging voltage, and only above 3k, is very interesting -- I don't see how the pumps could affect the tach sender. I suppose you could be getting some accidental contact between the 12V feed to accessory fuse box and the sender wire, but then why no symptoms under 3k RPM?

The battery itself seems to be the common point between these separate circuits -- check those connections, load test the battery........

that's all I can think of at the moment...
[disclaimer -- I have no formal electrical training whatsoever.......]

~~~~~
btw, can't hardly make out your avitar photo -- looks like an engine fire on an AA 757?

 

[hydra23]

Re: intermitent tach lights

Thank you, Im ready to start troubleshooting, will post my results.