Hobbs meter

[bones774]

hi, brand new to this forum looking for Lotsa help with small fixes.
Have a 1988 cobalt 22 b/r, has the old fashioned rectangular Hobbs meter, does not work. Can anyone tell me where it hooks up to and wiring colors, the original manual has a horrible diagram.
can I just test it with 12 v applied? I see it draws off the cig lighter right next to it but then where?
thanks

[cmattj]

Let’s gets some pics up in the new members section!

Simple design from a switched 12v source.
Pull it and run directly to a battery. Then of course wait.

[Big Block Power]

I think you will have a red and a yellow white going to it. Red is 12v from ign, yellow yes will be your grd

[AsLan7]

Let’s gets some pics up in the new members section!

Simple design from a switched 12v source.
Pull it and run directly to a battery. Then of course wait.

.
Yes unfortunately boats run off the ignition switch like the bottom diagram shows. I wish they’d run off the oil pressure switch (top example in pic) like light aircraft. That way there wouldn’t be such a discrepancy between actual engine hours and the Hobbs meter reading. Ours was 73 hours high due to the prior owner leaving the key in the ON position for stereo listening. We currently have it unplugged at the meter in an attempt to match the engine hours (which we know from our vessel view reading) with the Hobbs meter. Check those two black wire spade connectors.

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[bones774]

as I said mine is connected to the cig lighter and I'm thinking that might not be powered till I throw the accessory toggle, if so that means I have to run access on to register. Also if the cig lighter works but meter doesn't I guess meter is bad. I'm gonna check that next week.