RPM Guage Aint Working

[GeorgiaMan]

When I crank my motor up . my RPM guage jumps one time like it's gonna start working but , it just goes back to zero quits never works, How can I fix the problem here...

 

[Ryan87LX]

Re: RPM Guage Aint Working

Assuming the motor runs and charges properly, the first thing to look for would be continuity to the tachometer. Make sure that you have power everywhere you should, and that the wire between the stator and the tach is in good shape.

 

[79Merc80]

Re: RPM Guage Aint Working

What engine are you talking about??

 

[GeorgiaMan]

Re: RPM Guage Aint Working

the 2005 50hp Mercury outbourd...

 

[Silvertip]

Re: RPM Guage Aint Working

There are four connections on the tach. "L" = internal light. This has nothing to do with whether or not the tach will work. "I" + ignition (+12 volts with the key in the RUN position). If 12 volts is not present the tach won't work. Ground (ground symbol) = ground. If the ground is not connected to a good ground point (such as ground on a any other working gauge) the tach can't work. "S" = send which is the pulse line from the charging system. If it is not connected, or if the charging system isn't working, the tach won't work.