Hot Coil and High Alternator Output

[jpian0923]

I guess my point was, instead of running the risk of frying the coil, EI and the alternator, (3 expensive parts to replace) you could run it as if it was on the bench, just off the battery.

Remove alt belt, connect jumper from + coil to starter post. I bet it would continue to run with battery as low as 6 volts.

Your action is not indefensible. Sailing season is short, shorter for those that work 5 days a week. And you might be waiting a while for Jerry to send you his old alternator.

Maybe my logic is flawed. Correct me if I'm wrong.

[hanleyclifford]

Nothing wrong with running without an alternator but the key is to disconnect the field and alternator output terminals. It's OK to let the alternator spin itself crazy (unconnected).

[jpian0923]

Thanks for the input Hanley. It's nice to know it's possible if needed in an emergency.

[hanleyclifford]

Here's what I keep on board for when I get really disgusted with the regulators I have. This is cobbled with 10w bulbs and 1 ohm (10 watt) resisters. Cheap and easy way to supply limited voltage to the field if you get in a fix. Red is 12v input and blue is ouput to the field, switches in parallel.

[Triton106]

Woa Hanley, that's some hard core engineering... Care to explain how that works in lieu of a regulator?

[Triton106]

I guess my point was, instead of running the risk of frying the coil, EI and the alternator, (3 expensive parts to replace) you could run it as if it was on the bench, just off the battery.

Remove alt belt, connect jumper from + coil to starter post. I bet it would continue to run with battery as low as 6 volts.

Your action is not indefensible. Sailing season is short, shorter for those that work 5 days a week. And you might be waiting a while for Jerry to send you his old alternator.

Maybe my logic is flawed. Correct me if I'm wrong.

Thanks Jim, I think that makes perfect sense (to disconnect the alternator). I don't know how long I would be able to run the A4 without the alternator with just one battery. I remember a few years ago I was in Santa Rosa (an hour north of San Francisco) and my alternator (in the car) failed. I had AAA tow my car to a local service station and bought a new battery (the old one was due for replacement). I then drove as fast as I could back home (in South Bay - an hour south of San Francisco) and almost made it before the battery died on me. But it was a V8 and not a simple Atomic 4. I think it was that unknown that influenced my decision to leave the alternator on even though I knew there was the risk of it frying other electrical components. What I really should have done is just sail out the marina and sail back in. It's not as hard as one would like to think.

[hanleyclifford]

Woa Hanley, that's some hard core engineering... Care to explain how that works in lieu of a regulator?

The voltage regulator is nothing more than a variable resistor. The regulator controls alternator output by controlling voltage to the field based on an alternator voltage setting. The alternator controller cannot replace a regulator. It has to be watched carefully by means of voltmeter and ammeter. Each switch provides current to the field thru different configurations of resistors. So, for example, in the illustration one switch could have 1 ohm, the next 2 ohms and so on. The switches are in parallel so many combinations are possible.

[sastanley]

Hanley, The P.O. on my boat had a similar (but not as fancy) set up. The original regulator had failed long ago, as well as a couple of those old Studebaker style regulators we discussed earlier in the thread.

He cobbled up something with a couple of resistors and a switch. He had it set so it regulated the output to 4 or 5 amps, or wide open. "Don't leave it wide open for too long", was his word of caution.."OK, Pops, thanks. How about I just go buy a $25 regulator that bolts to the alternator."

[Triton106]

Ray-
Got home late last night and looked in the garage to make sure I still have the promised ALT. It's there. (whew!)
I had to leave this morning on another trip, but will be home Wednesday and it'll be on the way. Hang in there...

There is a happy ending to this story...

I received Jerry's old alternator (thanks Jerry!) yesterday but it was too late to put it in. So this morning I went to the boat first thing and installed the "new" alternator - and it works perfectly. Here are a few pictures. As you can see it was putting out 13.43v. I think that is appropriate since my battery is new. I will need to replace my dummy battery monitor with a volt meter to better monitor the charging state. The alternator looks happy to be back on an Atomic 4.

My old alternator on the left; Jerry's original alternator on the right.



The original alternator seems to be happy to be back on an Atomic 4.



The original alternator putting out 13.43v at idle. My battery is new.