Tach issue, might be more!

[Kyle C]

Hello, I've got a 1981 johnson 90hp motor I'm trying to connect the tach up to but I'm having a small problem. First things first, I don't have a rectifier or voltage regulator. I've been reading alot of previous posts about tachs as to not have to post myself but, here I am. Is that why I can't get a reading from my tach, and if so, can I take the volt regulator and rect. off of my 1984 Evinrude 90hp and go man go. Any help is appreciated. Kyle

 

[Jeff_G]

Re: Tach issue, might be more!

Why don't you have a rectifier? You should have two yellow or yellow/gray wires from under the flywheel. These go to the rectifier/regulator.

 

[wilde1j]

Re: Tach issue, might be more!

Oh, the motor had one new. Connections to tach are typically, grey=pulse, black=grd, and purple=switched 12v+ for light.

 

[Kyle C]

Re: Tach issue, might be more!

I've got the tach hooked up properly, I'm just not getting a reading. Upon trying to trace the gray wire to the terminal block I noticed I don't have a charging system and I was wondering if that would affect my tach reading off of the controls.

 

[wilde1j]

Re: Tach issue, might be more!

You need the alternator AC output for a tach to work. What happened to the stator and rectifier? The motor had both new. Clearly, the stator is still there (or you couldn't run the motor).

 

[Kyle C]

Re: Tach issue, might be more!

I can't argue with that but I don't see a rectifier where my book says one should be. I bought this motor used a few monthes ago and I've been rebuilding it slowly. The two holes that should be bolting a rectifier in, one is empty and one is holding a wire clip. I'm gonna go look again for the two wires coming out of the stator like you said , I'll get back to ya. BTW, thanks for the fast replies.

 

[wilde1j]

Re: Tach issue, might be more!

Look at the parts breakdown on the BRP/Evinrude website to see what the rectifier should look like. If you're using a third party shop manual chuck it and get an OEM book.

 

[Kyle C]

Re: Tach issue, might be more!

In regards to what you said, I did check to make sure the parts looked the same and they do. I can't find the rectifier for my motor on my motor. That being said, I do have a yellow and a yellow/gray wire coming from the stator. Is it possible the rectifier is under the fly wheel? Either way, is there a way to test the signal coming from the gray wire at the terminal block? If so I can trace it to the controls. BTW, I already opened the controls and checked the wiring, it's fine. Again, thanks!

 

[wilde1j]

Re: Tach issue, might be more!

Is the grey the one to the tach? All you need to test is the grey and a ground to the tach. It's going to be pulsed AC. The yellow and grey/yellow are typically AC to the rectifier.