Gauges not Working

[NZ-Kevin]

I have just bought a boat with a 1986 Johnson 60 on it (AJ60TLCDS ser.A0614076) and the tacho and trim gauge don't work. I cleaned up all the connections on the trim gauge, and as soon as the ignition is turned on the needle drops off the bottom of the scale and stays there. I presume this means the sensor is open or short curcuit and the needle is jumping to one end. Where is the sensor and is there any common problem to be looking for. The tacho doesn't even glitch when power comes on (which is a bad sign). The needle just sits at about 5500 rpm permanently. Again, any common problems to look for?

I know it's not the end of the world if these don't work, but I'd like to fix them if I could.

 

[NZ-Kevin]

Re: Gauges not Working

I have just tried to see how much a new sender for the trim gauge would be in case it was broken, but they are not available. Is there anything else that will fit and do the job? I located the sender and it was stuck, very stiff. But I turned the ignition on and forced the lever up and down and the gauge didn't move, so I'm assuming it's broken as well as stuck.

 

[boobie]

Re: Gauges not Working

Are you getting any B+ voltage to the tach and is it grounded ?

 

[NZ-Kevin]

Re: Gauges not Working

The supply to the tacho is from the same place as the trim so it sould have power, but I'll check it with a meter to be sure. Might not be for a few days as the forecast sys we have a "weather bomb" hitting obver the next 24 hours and the boat is outside.

 

[boobie]

Re: Gauges not Working

Both gauges could be bad due to the age but check any other possibilites first.

 

[Silvertip]

Re: Gauges not Working

Gauge problems are almost NEVER the gauge itself.

 

[valkie]

Re: Gauges not Working

Did you rtesolve the problem?

What was it?

I have an old Johnson 40HP that runs like a dream but the other day after 1 & 1/2 hours of motoring around, mostly at about 10 knotts, both the tacho and trim gauges died.
I turned off the motor and powered her up again and have not seen the problem since, but Id like to check the wiring anyway.

You say that the supply is from the same place, where is that.
My wiring diagrams dont show either the tacho or trim gauge.

It sems to me the problem could be the supply wiring could be the problem, but I cant even find the damn tacho wire on the motor.

Please help

 

[NZ-Kevin]

Re: Gauges not Working

In my case the tacho was broken -probably due to having too high a voltage across it. The older Johnsons had only a rectifier fitted, no voltage regulator. When running with a modern maintenance free battery this causes about 17v to be in the system. The trim gauge didn't work because the sender was broken, and is now unavailable -so I replaced it with a voltage gauge in the dashboard. I can see the motor anyway -so don't really need a trim gauge. I fitted a voltage regulator and a new tacho.

The take off for the tacho comes from one of the alternator wires (before going through the rectifier/regulator), usually a grey wire. The power to run the gauges comes from the control box, and is switched on and off with the ignition switch.