Non-functioning Aqua Meter tach

[Michidan]

My new (to me) 74 starcraft has a nice old Aqua Meter tach, model 635. I just got everything running good but the tach doesn't work. These just have the 2 wires. Grey is spliced into the tach line from the Johnson remote. And black is to ground. Should be good.


The needle never moves. On the back the pulse needle is set to 6, and it is a 3 cylinder Johnson (65hp). What else can be checked? Any way to diagnose these with a tester and perhaps fix it?

 

[gm280]

If you can open it up and get inside and know what you are doing, yes it can be fixed. But you really need to understand how the tach works to know what to look for that isn't working. There really isn't many parts inside, but you have to know how to test each part to determine if they are good or not... JMHO!