tach question

[nmhellraiser]

Alright, I've got a Marpac tach on my boat that I can't get to work properly and need some info. I'm pretty good with wiring but want second opinions. I've got a 1983 johnson v4 140hp on the back of the boat. I've got my gray wire from the harness tied to the signal terminal on the tach and I've got my positive and negative to the respected terminals. I've set my pointer on the back of the tach to 6 and the tach doesn't seem to work. I can change it to 5 and it works when it wants. Same thing when I switch it to 4 but as I go down with the numbers the rpm's raise to numbers I know aren't correct. What am I missing? It should be set on 6 correct? I haven't checked the exact voltage with my meter but I'm getting constant power on the gray wire. I'm just using a test light to verify voltage.

 

[ezeke]

Re: tach question

Gray wire voltage needs to be tested with a DVA. Here's a link for troubleshooting your rectifier: http://cdielectronics.com/InstallSheet/153-3408.pdf

 

[nmhellraiser]

Re: tach question

I'm pretty sure my rectifier is ok. I changed it out thinking it was my issue but I've got the same thing with either rectifier. I'm leaning toward the tach but want to make sure. What setting does it need to be on? 6 correct?

 

[ezeke]

Re: tach question

6p is correct. If it does not have that setting, it won't work.

 

[nmhellraiser]

Re: tach question

Yeah it has the 6 setting. I'm thinking it's the tach itself. I'll order a new tach and see what that doesn't do.

 

[nmhellraiser]

Re: tach question

Alright, I'm going to bring this back to the top. I finally got me a new tach installed and I'm still having about the same issues with this tach but it works more often than the other one. When it does work, the RPMs seem to be correct but it just seems to work every now and then. Any other ideas. Maybe a bad rectifier? This one is only about 3 weeks old.

 

[chasecd]

Re: tach question

Gray wire voltage needs to be tested with a DVA. Here's a link for troubleshooting your rectifier: http://cdielectronics.com/InstallSheet/153-3408.pdf

Hey, thanks for that info/link. I too am having issues with a dead battery and think I have narrowed it down to the rectifier. I order one from Evinrude yesterday (9 Sep 10) and it should be in next week. I used your link to get the install sheet for my particular model rectifier. Mostly just info for me as my flywheel will have to be pulled and therefore, I will turn it over to the expert I have that works on my boat.

Again, thanks.