1999 Mariner 150

Tach isn't working and got to reading some threads and doing the tests. Voltage at battery is higher with engine running. However, the connections on the rectifier looks like they have burned.

I'm assuming the rectifier needs to be replaced due to the burnt ends, but why does the voltage still read higher while running? Do I need just a rectifier and or new tach?

Not unusual for those yellow ends to get a little brown. Disconnect the battery then clean or repair the bullet plugs as needed. With v higher running regulator should be good. I would first reset the pole setting switch on the tach and check all connections their.

I moved the pole setting switch around and still no tach reading. As motor is running tach is pegged out at 7k

Look at the regulators. Have seen them burnt in the middle of the clear plastic filler. Does the tach go to O when key is turned on?

Going to have to remove that plate to see them. No, it doesnt go to 0. Stays past the 7k mark

Sounds like the tach is bad. Just be shure to disconnect the main battery when working on the regulators.

i have a set of rectifiers if you need them.

100.00 for both!

Have you tried changing the tach lead to the gray wire on the other rectifier? They both have a tach lead.

Haven't tried that yet. Thanks for the tip and I'll do that the next chance I get