Voltage/charging gremlin driving us crazy

[dwhatty]

Have Cummins 330 6BTA 5.9, Balmar regulator, Xantrex Link 1000, 150 amp alternator.

Everything in charging system appeared to be fine last fall at lay up time. Nothing done over the winter that I can think that would affect the system.

On first run this spring after about twenty minutes of run time,* voltmeters on both bridge and lower helm starting flickering up and down and then continuously dropped into and out of the 10 +/- volt range with low voltage alarm going off. Xantrex readings all over the map.

Called electrician who found alternator not charging so we sent it to the hospital which found one diode pooched but otherwise okay.

Electrician reinstalled it but when we tried to start engine we had no juice to starter. Electrician found solenoid on engine in starting circuit melted but said it looked like it had been partially melted for some time and* that cable to it was loose.

Installed new solenoid. Engine started. Electrician found alternator putting out correct voltage, Balmar working properly (all its readouts were on the money) and the Xantrex agreed with both of them. The instrument panel voltmeters, however, started flickering again, dropping to 10v +/- and low voltage alarm. But the alternator, Balmar and Xantrex were reading proper charging.

Electrician then started checking terminals and connections from the batteries all the way up through the system. Found some loose and/or corroded connections and rectified them.

Finally, all seemed well. Voltmeters on instrument panels were rock steady (even though reading 12.2 to 12.5 while alternator, regulator and Xantrex agreed upon 14.2v).

All of this was done with the boat on the mooring, with transmission in neutral and just running the engine up and down in rpm.

Took the boat out today. After a 10 minute run all the same problems started over again. Same darn symptoms: voltmeters on both bridge and lower helm starting flickering up and down and then continuously dropped into and out of the 10 +/- volt range with low voltage alarm going off. Xantrex readings all over the map.

Came back to mooring. After idling for a few minutes it all settled down with the Xantrex and panel voltmeters showing good charging.

Took her out and it all started again.

Obviously, need to call the electrician back. But does any one have ANY ideas as to why the charging system now appears to go nutso only when we are running with the engine in gear?

 

[Capn Chuck]

David, I doubt that having the engine in gear has anything to do with your problem, but running and the related vibrations and or RPMs may have something to do with it. It could be a loose ground or a host of things that only someone on the boat is going to be able to diagnose. the electrician is going to need to do any diagnostics under way and not sitting at the mooring. Chuck

 

[FF]

"Found some loose and/or corroded connections and rectified them."

BUT he didn't find them ALL!

The most fun is when you finally bight the bullet and spend a day removing all the terminal ends , cleaning them with scotchbrite and replacing them, and it still doesnt work!

My recommendation is to first purchase a few hundred star washers that are copper or better copper that is tinned.

Install one under the nut as you reinstall the wiring ends, and be sure to give a yank on each terminal, as many are installed with auto crimpers and eventually fail.

What causes the failure is the constant expansion of the metals as a poor joint gets warm carrying current . The star washers make up for the change in thickness at the ring terminal, but only a proper crush , or better a drop of solder can assure the wiring is properly connected.

IF you have bare copper wiring , not tinned , good luck.

FF

 

[Capn Chuck]

Vinny, Not sure what ground you have on the transmission. Heat generated by the wiring could cause a problem but not heat from the engine room. A poor ground anywhere can be a problem. Besides cleaning all of the connections you need to give them all a good yank. Don't worry about pulling them apart because if you do then you just solved a problem.

 

[dwhatty]

Thanks for the replies. Thought I had found something today when I pulled on a positive wire on the alternator and it came out of its crimp terminal. Fixed that but that was not "it". Came in from a test run (showed same problems) and 20 minutes later when I tried to restart the engine there was no juice to the starter (another fried solenoid?). Too late and too tired today to check. Will do the engine room dive again tomorrow. Right now a good belt of Bourbon.

 

[FF]

Just a thought , but is the fried solenoid releasing far enough after engine start?

If it came back far enough to release the Bendex but not all the way , it could explain some of your problems.

A few min after start , take off the big wire to it and see if you get a big spark , or at least touch it and see if its getting hot.

????

 

[Capn Chuck]

David, Before you start removing solenoids and such, take a voltage reading at the solenoid, and then take another reading at the same time someone is hitting the starter switch and see what you have. Chuck

 

[dwhatty]

Back from getting intimate with the Holy Place.

Solenoid appeared okay visually (which does not mean much, I know) but will wait for electrician to come back from vacation to have him check it out. Did notice that the two wires (red & brown?) leading from the starter to the alternator had partially melted the connectors in the middle of their run as well as slightly melted the plastic spiral wrap around the wires at that point. Hmmm!

 

[Chris Foster]

Can you give some idea of the general configuration of the charging system?* I'm going to make some assumptions in the following - are they correct?

Melted wires from alternator to starter.* Sounds like the 150 amp alternator was added without beefing up the output wire, which I assume is connected to the battery through the main terminal on the starter.* You need a #4 or #2 cable to handle the current - basically an automotive sized battery cable.* The fact that you said the wire came out of the terminal - and that there are connectors in between - makes it sound like it's probably a much smaller wire.

Also note - an open alternator output can fry diodes.* Especially an intermittent one that briefly makes and breaks contact.* The rotor builds up a lot of magnetic energy, and if there's nowhere for it to go, the output voltage will spike and the diodes will be history.

Where is the Xantrex connected - directly to the batteries or other side of the battery switch?* If it's intermittent and the battery switch terminals are OK, it could be a bad switch - they can poop out.

If everything's OK but the instrument panel meters are still flaky - do those meters only come on when the ignition switch is on?* If so, it's probably a bad switch.*

It sounds like you have 3 or 4 problems of which you've taken care of the first two or so.*

Good luck - let me know what you find.

 

[dwhatty]

I FOUND IT!

Electrician did not. Loose connections underneath the reset button on the top of the engine. All is now well. Charging steadily, voltmeter on panel now reading correctly, wires cool. Such a very small thing but it caused such large problems. What was that quote "For want of a nail etc"?


-- Edited by dwhatty on Tuesday 16th of June 2009 04:35:37 PM

 

[FF]

Keep cleaning, IF one electric connection failed , the installation methodoligy was wrong and all will eventually fail.

Sorry,