turnerrd

I have Merc AGI box's feeding Livorsi stud style gauges.
For no ryhme or reason my guages will randomly sweep just like when they are keyed on for the first time while the boat is running. Sometimes at idle, sometimes while cruising, somtimes while running hard. Both sides do it, but never at the same time.
GPS, Vessel View are both fine. They come back up and pick up where they left off, just Very annoying!
I have tried running known (good) dedicated power and ground to each circuit as my guages are daisy chained together. Have also tried disconnecting the hour meters as i thought they could be hanging up as they clicked over. With my back lights on they never even flicker when they sweep.
I even put new batteries in as I thought i might have a loose plate causing small spikes.
None of this did any good.
Everyone I have talked too both at Livorsi and mercury have said it can't be 2 bad AGI box's but I am at a loss on what else to try.
Also my tachometers start reading high after 3000 rpm. At 4000 they are 500 higher than the vessel view and that way up to the top.
Gauges have been back to Livorsi and where pegged at 5000.
No explanation on this either from merc or livorsi.
Not sure if this has anything to do with the sweeping issue or not.
Unless im missing somthing else to try can anyone tell me if this sounds like AGI box's before I replace?

Thanks

Rob

TWIN-SPINS

anytime I had unexplained issues,,,,it always had something to do with the grounds,,,jmo

turnerrd

I hear you on the ground but like I said I already ran another one. Also since the back lights dont flicker when they sweep its all the same ground.

turnerrd

I ended up replacing both AGI boxes and it took care of my problem. No more gauge sweeping and my tachometers are right on. Hopefully this can help someone else down the road.