Wiring for 6BTA tach hour meters?

[Keith Pleas]

I have the new board to fix the WIF alarm (https://www.sbmar.com/community/topic/yet-another-wif-sensor-problem/) and before replacing it I wanted a quick check – does this board have anything to do with the hour meter on the stock Cummins tach? I’ve had my boat for 2 years, neither hour meter has changed since the sea trial, and I was thinking it was a disconnected wire running from the key to the tach…but the tach has a bunch of modular connectors and it wasn’t obvious. Does this run through the board?

Topic

[Keith Pleas]

Searching on a related topic I ended up with the diagram that shows the wiring connection to the tach: https://www.sbmar.com/wp-content/uploads/2015/11/B-C-Panel-wiring.pdf

That other thread also mentioned that it’s not just the key power, but there’s something in the tach having an RPM reading that turns on the hour meter.

Anyway, I ordered the Chetco interface today so I won’t be bothering to fix this.

[Keith Pleas]

Thank you guys! I hadn’t considered that the _gauges_ might have failed. But I was planning to replace them with a Chetco SeaGauge anyway – the plastic is a bit crazed, some of the backlight bulbs have failed, and the gauges just look old. The SeaGauge _outputs_ the Engine Hours in PGN 127489 Engine Params Dynamic that my dual 12″ Raymarine Axioms should pick up easily – I talked to the inventor and he said I could push starting hours into the unit and after that it would keep track internally. I was going to run that in parallel for a season and then replace most of the helm panel with a 3rd Axiom.

Is there a 12v+ pin on the back of the Cummins tachs that I should at least check for keyswitch power? My preference is to have things working _before_ swapping things out.

[Bob Patterson]

Apparently it is a small gear that runs the hour meter that goes for sh.t.I got mine repaired at Forster Instruments in Mississauga Ontario Can.I am not sure if they have a US depot or not.

[Stephen Oliver]

To add

These tachs are famous for packing up – both mine have at 1000ish hours and 1300 hours. I think most boats I looked at that had these tachs, they were inoperative all around the 800 – 1500 hour mark.

I’d love to know what the fix is.. so I can get them going again! Search as I might.. I cannot find an answer.. Even a drop in replacement would be good – i’m even looking at seeing if I can remove the bezel and replace the gauge.. failing that – a 3d printed surround with another type of gauge!

Steve

[Tony Athens]

The PCB board has nothing to do with the tach operation or the hour meter. It’s strictly there to interpret the coolant temp sender, oil pressure sender and voltages and drive the alarm buzzer /warning light at preset points.

[Author]

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