82 Johnson 70HP Tach Problem

[blazim]

I just added a tachometer to my boat. It is wired in correctly (grey to send, black to ground, purple to ignition). It is set to 6p and zeros out when the key is turned on, but won't show any rpms. Any ideas??

 

[jtexas]

Re: 82 Johnson 70HP Tach Problem

see if there's any AC voltage on the SND wire. If not, measure the voltage across the battery terminals, should be higher with the engine running. If it's
not, replace the rectifier. If it is, test the gray wire for continuity. If all the wires are good, and there's a signal on the gray one, you may just have got a faulty tach.

It is a marine tach, right?

 

[blazim]

Re: 82 Johnson 70HP Tach Problem

Will give it a try. Yes, it's a teleflex tach. Thanks.