Tacho not working - Black max 160 v6

[Superjetjim]

Hi looking for some help please - I have a black max v6 (91) which runs great apart from no reading on the RPM/Tacho. The speedo and fuel guage are working Ok and also a recent new throttle control box and loom so all that wiring down to the engine is good to go.

Where would I start looking into the cause of my non functioning Tacho? - how could I test the actual gauge and pick up on the engine in some way?

Thanks for any help.

Cheers,

James

[Ian Sharlot]

James, you have a pm

[Superjetjim]

Still looking for diagnostic advice here - guys (PM was unrelated to technical issue)

Thanks

James

[Turbodiesel]

check the pulse settings on the back of the tacho, cant remember what it should be on yours but try some different settings. The Voltage regulator is the part that runs the tacho so this could be at fault.

[Superjetjim]

Originally Posted by Turbodiesel

check the pulse settings on the back of the tacho, cant remember what it should be on yours but try some different settings. The Voltage regulator is the part that runs the tacho so this could be at fault.

Thanks TD - Is the voltage regulator the little black box on the outboard with the leads hanging out?

[Poly]

Assuming your tacho is fairly standard it will have 3 wires going into the back to make it work (Ground (usually black), a +12V feed which will be live when the engine is "running", and a "signal" wire). You may also have a +12V feed which goes to the "backlight" which may or may not be connected and may or may not be wired as always on, or e.g. on when the nav lights are on.

Assuming you have those wires (iboats.com or your owners manual will be able to help with colours), and they are in good condition then I would put a multimeter between the signal wire and the ground - with the multimeter set to AC (a 20V a.c. range should be fine). With the engine running this should show a voltage (and zero with it off). The signal will increase with the revs. If it does this and all the wires and connected then it is probably your gauge that is faulty - or set completely wrongly, as T.D. suggests there is usually a "dial" or setting of some sort on the back to adjust how many poles etc it should use in its RPM calculation.

[Superjetjim]

Thanks guys that's great advise - will give it a try when the snow is melted and I can fire her up.

Cheers,

Jim

[Superjetjim]

Quick update - all sorted and working now, it was the rectifier on the outboard, the guage was fine

Cheers

Jim