Alternator Light On and Tach Out

[Vamonos]

Here is another thought that is possibly Perkins specific. The wiring harness from the engine joins the wiring harness from the control panel at a 8 (?) pin plug at the back of my '84 Perkins 4.108. The plug was supposed to be clamped in place to keep it from both flopping around and to keep the two halves mated. Mine had slipped out of place and one of the wires had rubbed through the insulation and was shorting to the bracket, which is "ground" (actually battery negative since boats aren't "grounded"). After doing a bit of electrical surgery, insulating, and re-clamping that plug, all sorts of little issues resolved themselves. Strange voltage readings, intermittent start, gauges jumping. I think it may have also toasted the regulator (internal) in my alternator.

Out of curiosity, when you had the alternator tested, do you know if they tested the tachometer output? Do you take it to Manny, Mo and Bubba or a real auto/marine electric shop. If you can find a real auto-electric shop, you will never go back to the AutoDrone crowd. They will rebuild your alternator or starter with quality parts for less than you can get a Taiwanese reman. Mine was the original Delco unit. They rebuilt it, replace half of the case and rewound it for a higher amp output for $60!!!! Is it a Balmar? No! Can I take it to pretty much any shop in the world if the regulator or diodes crap out? Yes!

Richard
Vamonos Pearson 385

[duefocena]

You're right Vamanos, I went to Vato Zone and just looked at the output.
You hit the nail when you said "all sorts of little issues resolved themselves. Strange voltage readings, intermittent start, gauges jumping". I have had intermittent starting, guage jumping and the Tach would occasionally "hop" around.
Drove the boat 20 miles today to haul out only to find out it is 6" too beamy. On the way home the port engine started spurting oil from the shaft the cut off is attached to. Man, when it rains it poors. Good thing I love it.