1998 Sun Sport Overcharging

[Art]

I have a 1998 Supra Sunsport that seems to be "showing" it is over charging. The volt gauge on the dash shows it above 16. (Which is the max of the gauge). I just had the alternator(which has a integrated regulator) rebuilt and the battery checked. Installed them both today and all voltage is within spec however the gauge still is rading an over charge. Does anyone have any thoughts? I "think" it may be the gauge but not sure if I am missing something and if so, would like to replace it with a matching one if someone knows where to find them.

Thank you

[middlegriff1]

I just noticed this problem on my boat. I was told my voltage regulator is bad. Ordered a new alternator, going to test it this weekend. Ill let you know the results.

[middlegriff1]

Have you figured it out? Update on mine- I ended up buying a new alternator to find the same problem. Just got both of them tested yesterday and both are good, Doh. Overcharging of the alternator can be because the voltage regulator is bad or the connection of the positive wire to the starter gets corrosion. Hopefully I can verify today after cleaning my connections and running the boat.

[92SupraComp]

Voltage gauge could be going bad or the connections to it are bad. Although usually if bad connections it will read low..

[Moor]

More than likely a bad gauge, test the output of the alternator with a multimeter, then test the power wire at the gauge. reading should be very close or identical. Fwiw, i had the alternator rebuilt on my old barefoot nautique because it was undercharging. They never replaced the voltage regulator. I had to bring it back so they could rebuilt it properly. If you arn't rebuilding it yourself, you don't really know what is getting replaced and what is getting cleaned and reinstalled by the rebuilder. I'd double check that they replaced your voltage regulator.