Boat is a '91 Nautique with the PCM Ford 351 motor. The VDO tachometer has been working intermittently for awhile so I took the dash apart to investigate further. There are three wires going to the tach.
Purple to the + terminal
Gray to the SGL (Signal) terminal
Black to the - terminal
I pulled them all off and cleaned the male spades on the tach and made sure everything was clean and tight. I also fired up the motor to check the voltages and across the +/- I get about 13volts at idle. And the signal to ground connection shows about 6vdc. I have a nice Fluke meter with the bottom graph so I was expecting a pulsed signal but instead it showed a constant 6vdc.
I also checked the connection block where the signal wires plugs in and cleaned those connections.
In any case, I installed everything and now it doesn't work at all.
Any insight would be appreciated.
thanks,
RickR90s
Purple to the + terminal
Gray to the SGL (Signal) terminal
Black to the - terminal
I pulled them all off and cleaned the male spades on the tach and made sure everything was clean and tight. I also fired up the motor to check the voltages and across the +/- I get about 13volts at idle. And the signal to ground connection shows about 6vdc. I have a nice Fluke meter with the bottom graph so I was expecting a pulsed signal but instead it showed a constant 6vdc.
I also checked the connection block where the signal wires plugs in and cleaned those connections.
In any case, I installed everything and now it doesn't work at all.
Any insight would be appreciated.
thanks,
RickR90s
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