tach or regulater/rectifier

[89 Sprint]

The motor is 90 Johnson 200. Tach quit working and I am trying to figure out why. Can you test tach on back with an ohmmeter? And if it is working, how do you test the regulater/rectifier to see if it shorted out? Motor is also down on power, so I don'nt know if the two are connected or not. I do know it is putting out about 14 volts to charge the battery.

 

[hondon]

Re: tach or regulater/rectifier

If you have acsess to a meter with AC/DC capabilities set your meter to AC and there shoud be no or very tiny readings at the battery terminals .This lets you know your rec. is working.

 

[hondon]

Re: tach or regulater/rectifier

Forgot to add with engine running.

 

[Dunk]

Re: tach or regulater/rectifier

To test just put a volt meter on the battery. Start the engine if the volts don't jump up tp 13-14.5 volts the Reg is shot. Rev engine to at least to 2000rpms, no higher than 2500 in neutral and watch your voltmeter. The Reg/rec also supplies the signal for the tach. Your looking at about 200 bucks for a new one.

 

[89 Sprint]

Re: tach or regulater/rectifier

A mechanic at a shop told me that just the part of the rectifier that drives the tach can go bad. Is he truthful or just trying to sell me a part? I have no problem with battery charging, putting out 14.3 volts.