Merc. Tach and trim gauge

[Briansaqua]

I have a mercury 1998 115 elpto. The tach and trim gauge quit working. Is there an interface with my proline 170 sportsman? Where would I start to look. Thanks Brian

[Bergertime]

Brian,

1) Is everything working normally (Trim, engine running, lights etc)?  

2) Do you have a gauge that reads voltage at the helm?  If so, is it reading what it typically reads when the engine is running at idle and at cruise?  Voltage output should be around 14V give or take a little when the engine is running just above idle.

3) Have you checked all the connections behind the gauges to make sure nothing has wiggles loose or displaced?

Lets start there...

B

[seabob4]

The Merc engine harness has (5) pigtails with ring terminals coming off it at the helm end.  Purple (ign power), black (ground), gray (tach sender), tan (eng temp), and brown w/white stripe (trim sender).  The purple and black are what gives your gauges 12V power, they typically run to the tach first, then daisy-chain to the other gauges.  So check the terminations on the tach to start with...