Tachometer reading very low

[krazzz]

I just installed a new tachometer (with hour meter) today. It is reading only 100-200 RPM throughout the entire RPM range of my motor. It is supposed to be for a 4 cyl motor. Even if it was for an 8 cyl it would still read higher than that. Has anyone experienced this before? On the back it has terminals for +, -, and signal. There are also two others that are not marked. I have the + going to the ignition, the - going to a good ground, and the signal going to the - terminal on the coil. Thoughts?

[captainmurph]

Tach Reading Low

Is there any possibility that your tach is designed for the signal to be connected to a tach coil in an alternator?

I know they are for sale here, but wanted to get mine through my employer (west Marine) and got one with a 4000 rpm output.

I paid an alternator shop $50. to put in a terminal in my orginal Motorola alternator and have the signal connected to it.

Murph'

[krazzz]

Hi Murph',
I am just up the lake from you in Ludington. It is possible that it is intended to be run off the alternator but I don't think so. Unfortunately it didn't come with any instructions.

[marthur]

Hey Guys,

I am in Muskegon too. Small world.

Is your tachometer designed for sailboat engines? If it is, it could be a diesel tach. They sometimes require a sending unit.

Tell us everything you can about the tach and maybe someone will have an idea.

Mike

[ndutton]

We're dead in the water until we know what kind of tach it is. Brand and model #? Pictures front and back including all labels??