How do I test my tach functions?

[tonynorie]

The motor is a 2001 200HPDI and the multifunction tach lost it's ability to display the RPM digits and I've been running it that way for quite a while since I know the boat and motor and know when it feels right while cruising. What I'm concerned about is the possibility that the oil and temperature functions may have also been affected by whatever is wrong with the gauge. Is there a way to test those functions so I'll have peace of mind when on the water? Thank you! Tony

[99yam40]

Drain oil tank and then turn key to on, it should show conditions and alarm. but not sure how you would check to make sure it reduced RPM.

Temperature , might take sensor out and heat with heat gun, or disconnect wire to it and hook up a resistor of the proper size
The old ones you just grounded the pink wire, but I believe these newer ones do not have switches they have sensors that feed info to ECU

[tonynorie]

If I drain my oil tank (I'm making the assumption you're referring to the one under the cowling) will that also send a signal to the large tank's pump to start pumping when I turn the ignition key on?

Thanks for your advice and I'm going to start with the oil warning test you recommend, and if that's working properly do you think it may be a safe bet to think the temperature warning is also functioning?

[99yam40]

as long as there is enough oil in the remote tank and the level switch in it is satisfied it will allow the pump to come on and fill the motor mounted tank when you turn on the key.

If that alarm functions properly, there is a chance the the overheat will work, but you cannot be sure unless you test it.

If it was mine I would be replacing the gauges and testing it all to make sure.
I do not like suprizes when out on the water trying to enjoy a good day of fishing.

Had to come in on one engine Saturday because of a raw water impeller coming apart on a friends 42'. He said he normally replaces them every year, but did not have very many hours on them last year so he was going for 2. He said he will not do that again