Tachometer/Regulator Question

[cleve]

Haven't posted in a while, but recently bought a 1993 Ranger 365V with a 1993 Fast Strike 150 on it. The tach doesn't work but if you look closely, the needle slightly moves when you turn the key on. I don't see a name on the tach but it appears to be original or quite old either way. I pulled it out of the dash, verified it's getting power with my meter, cleaned all terminals/connections, and turned the pole dial a few times but still nothing. The light doesn't work either. I've ordered a new tach and will return if it ends up being a regulator issue.
My question is, if the regulator/rectifier is bad and not sending a signal to my tach, would that also mean that my starting battery would die as well? Battery was fully charged after taking the boat out for a ride the other day is why I ask.

 

[Chris1956]

If the regulator does not give a signal to the tach, it is likely it is not charging.

It is an easy test. Put a voltmeter on the battery posts, engine off. Read dc voltage. Start engine and set to fast idle. Read voltage again and compare.

Voltage at battery with engine running at fast idle should be higher than voltage with engine off.

 

[cleve]

If the regulator does not give a signal to the tach, it is likely it is not charging.

It is an easy test. Put a voltmeter on the battery posts, engine off. Read dc voltage. Start engine and set to fast idle. Read voltage again and compare.

Voltage at battery with engine running at fast idle should be higher than voltage with engine off.

I haven't tested this yet but I did go out again Thursday and rode about an hour or so. Battery was good and strong and engine fired right up at the ramp when we got back. Would think if it wasn't charging, that wouldn't happen. Hopefully it's the tach itself. My new one should arrive this week.

 

[cleve]

Well, it's not the tach. Hooked up a new one and no signal. Has power, needle moves to zero when turn key on, pole setting on 6, battery fully charged. I'm thinking it's a wire/wiring issue. Can someone tell me some tips on how to narrow it down? Also, the signal wire is white/tan colored not grey like I'm used to seeing. Haven't got under the dash yet to sort where it goes.

 

[Chris1956]

Use an ohmmeter to test the wire between the VR and the tach. Alternatively, test the tach wire at the VR, with engine running on a flusher, for some AC voltage. I would expect only a few volts AC to run the tach, but start on a 100VAC scale so you don't burn out the meter.

However, the voltage test I described will tell you if the VR is working. I would do that test first, especially if you run in saltwater. I had a CDI VR rust out about 3 years after I installed it on my '98 Johnny 150HPV6.