Tach and Trim gauge

[Ace33]

My tach and trim gauges are not working. I went out and bought new gauges and put them in today...and nothing. I tried to follow the wiring and everything looked ok. Any ideas what might be causing these gauges from working? Also noticed that after I put in the new gauges the tach goes up to about 1000 RPM's when turned off? Then when the key is turned on it goes back to 0. Never seen that before. Any help would be appreciated.

[Ace33]

I have been looking and came up with maybe my rectifier is shot. Does anyone know where the rectifier is located on a 150 Johnson?? I can't seem to find it.

[marine_man]

Can you provide a little more background on this? Has either gauge ever worked? Did they stop working after you made some changes to the boat / added accessories?

The tilt & trim gauges are not connected (other than power 7 ground) to the tachometer, and the rectifier has nothing to do with the trim gauge.

If you can provide a little more background it would go a long way to pointing you in a direction to solve your problem.

marine_man

[Ace33]

The 2 gauges have not worked since I have owned the boat. I am selling the boat now and thought I would try and get them working before the sale. I thought the gauges were just shot but I put new ones in and still nothing. The wiring all looks good. Where does the tach wiring run too? Does it go back to the motor and hook up somewhere? Where is the rectifier located, I don't see it anywhere under the counsel or behind the control panel?

[BobT]

Bad (+) or (-) would be my first guess.

[Phred52]

I agree with BobT, Had a Jonny that the owner installed the battery and hooked the battery cables to the wrong posts. He got a small spark, realized his mistake and switched the cables. That first outing his tach didn't work, but could live without it. Later that season his starting battery wouldn't charge, so he finally brought it in. Yep, rectifier was shot. Replaced it and marked the battery cables REAL well, he hasn't been back since. Phred52

[marine_man]

I'm not certain the rectifier is the problem here.. it shouldn't have taken out the trim gauge as well.

Ace - take a test light / multimeter and verify you've got power at the purple wire or I post on the back of the tach and trim when the key is on, and ground at the black wire or - post on the back of the trim and tach. Let's make sure the gauges have power before we start checking on the motor.

marine_man