high voltage reading

[boatmare]

I have a 1998 115hp johnson. 2 stroke V4. I had my power head rebuilt 1.5 years ago . since then my voltage meter has been reading all the way up. it comes down when i change the tilt but then returns to all the way up. The voltage regulator was replaced but no change. I was also wondering if this would burn out my tachometer. because this went out afterwards. would this have any relation to the rectifier? Could the high voltage cause the rectifier to go bad? or could the high voltage have caused the tach to go bad? Or what may be causing the voltage to read so high? And what damage would the high voltage cause to my engine? It`s alot of questions but please if anyone could help!!! Thank You

 

[Chris1956]

Re: high voltage reading

The voltmeter should not read over 14V. If it does, there is something wrong. You might check the purple wire at the regulator. it should have +12V on it when the key is in the on position. This is the reference voltage, which conrtrols the voltage from the V/R.

The grey wire provides the Tach signal. it should have AC voltage on it when the motor runs.

 

[boatmare]

Re: high voltage reading

OK I`ll try that. Thanks

 

[aclmvh]

Re: high voltage reading

I have seen the same thing....I also have a '98 Johnson 115 SPL which has an unregulated 9 or 10amp charging system....with a rectifier and no regulator (this is the little cylindrical fitting on a diamond shaped base that is bolted to the starboard cylinder bank, right next to a power block). My voltmeter usually stays around 13-14, but has gone up to 16 on plane and at 3/4 throttle or above. I can only say I have not had any problems to date. I checked the rectifier (based on the shop manual) and it checked out).....but my tach did die last year (separate post/thread)....so maybe I HAVE had a problem. Ignition voltage is 12.5 at the tach. I have read in other posts (forums) that the unregulated systems are okay going up to 16 volts....that the battery actually serves as its own load to ensure there is no overcharging.

Sure would like others to weigh in on this.

mvh
Jax/FL

 

[Silvertip]

Re: high voltage reading

If the voltage is continually, or somewhat regularly above 14V it might be a good idea to turn on some accessories, like interior or nav lights to place an additional load on the system. This keep from overcharging the battery. On short runs, 15 - 16 volts won't harm anything. Overvoltage can pop a tach however. Radios, fish locators, and other electronics generally have over and undervoltage protection circuits so those won't be damaged.

 

[ezeke]

Re: high voltage reading

edit

 

[Gary H NC]

Re: high voltage reading

On my 1981 175 i went from no charging to 14 to 16 volts now after replacement of the rectifier.It is the 3 wire one.
I noticed after i run at higher rpms for awhile it drops back to around 14 volts..