Electrical Problem???

[jonfreeman]

Had an interesting occurrence this weekend. Our 1999 C-310 is in great shape, and we had just left the anchorage at Jarrell's Cove in South Puget Sound, heading for home. We had been on battery power for 1.5 days, and the batteries are new this year. Still, Bank 1 started the engine (albeit cranked a TAD slow (!)), and we motored off.

About 30 minutes out, I noticed the engine was running about 10-15 degrees hotter than normal. Still, the ammeter was showing a healthy charge (as expected), and all seemed OK. I decided to keep an eye on it. About 10 minutes later, the ammeter [actually - VOLT METER] went to ZERO, and the oil pressure light came on!

I stopped the engine, and checked the oil. Full up. Also looked for any obvious issues in the engine compartment, and finding none, started again. Engine was running a little warm (as before), but the light stayed on, and the ammeter [actually - VOLT METER] was still dead. HOWEVER, the GPS said we were still outputting 13.5-14 volts... Shut her down again.

OK - What to do? Weather was beautiful, but NO wind. Nearby shores (north or south) were not particularly threatening, so anchoring would be definitely do-able. Could also call Vessel Assist, as we have unlimited towing.

Decided to switch battery banks, and see what happens. Lo and behold, the ammeter comes back on line, the light goes off, AND the temperature cools down to normal. Motored all the way home (about 4 hours) with no issues or incidents. It was hotter than blazes when we arrived, and we had a commitment, so buttoned her up, and headed home.

I have ONE idea that I haven't checked out yet, but thought I'd offer this up to the community. What do you think is the problem? (Or problems?) Anybody ever experience this?

Jon Freeman
C-310 "Summer Sojourn"
Seattle/Tacoma

 

[Stu Jackson]

Yikes!

Still, the ammeter was showing a healthy charge (as expected), ...the ammeter went to ZERO, ...
I have ONE idea that I haven't checked out yet, but thought I'd offer this up to the community. What do you think is the problem? (Or problems?)

Jon,

Yes, you have ONE big problem: the ammeter!!! in your cockpit panel.

You may still have the old wiring harness, which is a FIRE HAZARD. It would be odd that you'd have an ammeter in the cockpit, since your C310 is newer and should have had the newer cockpit panel with a voltmeter installed.

You may want to check this:

http://c34.org/bbs/index.php/topic,4546.0.html

The "story" about the engine wiring harness is here: http://www.c34.org/wiki/index.php?title=M25_(not_the_XP)_Engine_Harness_Warning/Upgrade

The "factory" fix explanation is here: http://www.c34.org/projects/projects-harness-upgrade.html

Even if this doesn't apply to you, then maybe others will learn from it. As you can see from the posts I referenced, there are STILL people who just don't get it.

Given that, what's YOUR idea?

 

[jonfreeman]

Jon,

Yes, you have ONE big problem: the ammeter!!! in your cockpit panel.

You may still have the old wiring harness, which is a FIRE HAZARD. It would be odd that you'd have an ammeter in the cockpit, since your C310 is newer and should have had the newer cockpit panel with a voltmeter installed.

You may want to check this:

http://c34.org/bbs/index.php/topic,4546.0.html

The "story" about the engine wiring harness is here: http://www.c34.org/wiki/index.php?title=M25_(not_the_XP)_Engine_Harness_Warning/Upgrade

The "factory" fix explanation is here: http://www.c34.org/projects/projects-harness-upgrade.html

Even if this doesn't apply to you, then maybe others will learn from it. As you can see from the posts I referenced, there are STILL people who just don't get it.

Given that, what's YOUR idea?

OK - Good catch - I misspoke. I have a VOLT Meter, NOT an Ammeter. I will read your attached posts anyway, and keep you posted on the results.

 

[Stu Jackson]

OK - Good catch - I misspoke. I have a VOLT Meter, NOT an Ammeter. I will read your attached posts anyway, and keep you posted on the results.

That's helpful.

Jon, then that reference I supplied won't help you. The ammeter discussions may help others who haven't yet dealt with the wiring harness, and are just unknowingly waiting for their boats to blow up, but that ain't you. Which is a very good thing, right?

So, what's YOUR idea? I'll keep thinking, but I don't know how your boat is wired, or what you or other POs might have done. You do know. So, save us some suspense, and tell me what YOU think it is. I'll keep thinkin' on it.

 

[jonfreeman]

That's helpful.

Jon, then that reference I supplied won't help you. The ammeter discussions may help others who haven't yet dealt with the wiring harness, and are just unknowingly waiting for their boats to blow up, but that ain't you. Which is a very good thing, right?

So, what's YOUR idea? I'll keep thinking, but I don't know how your boat is wired, or what you or other POs might have done. You do know. So, save us some suspense, and tell me what YOU think it is. I'll keep thinkin' on it.

Haven't got back to the boat yet, but I was going to start at the battery selector. I recently installed an ESPAR hydronic system, and was in and out of the electrical panel area a number of times. The selector switch is mounted to the access door, so thought I'd check the contacts on that end for loose nuts, and work my way back to the battery box.

The starter key switch also may be a suspect (intermittent). One of the responders suggested this. Since I don't recall or believe the alarm sounded during this episode, I wonder if there is a connection (bad pun)?

Lastly, a ground for that bank (or the volt meter?) may be a candidate. A friend of mine with a C-34 suggested that. The crazy thing in all of this is the charging appeared to continue (according to the GPS) even though the VOLT meter went to zero, and the oil pressure light came on. And the fact that the other battery worked just fine... Hence, my suspicions around the start switch.

Thanks for the inputs. I will try to stay logical in the hands on part, so I can feed the forum's knowledge base when I solve this.

 

[philwsailz]

With everything at rest, no motors running, no load and no charging, what is the voltage measured at the terminals for both battery banks? I wonder if you had a cell open up on Bank 1?

 

[jonfreeman]

With everything at rest, no motors running, no load and no charging, what is the voltage measured at the terminals for both battery banks? I wonder if you had a cell open up on Bank 1?

I will check, but does that happen (suddenly?)? The batteries are both new this year...

 

[philwsailz]

I had a battery die in a truck once while cranking the motor over... Cranking, then blackness, no gages, no dome light, nothing.


Your change to the switch position fixing the problem suggests to me that something happend rather quickly, and only happened to Bank 1.

I would check all my ground wiring. The two tell tales you point out suggest to me that maybe Bank 1 has a loose or open path to ground.


In light of this, I might test my Bank 1 voltage first at the Bank 1 battery terminals, then moving the ground test lead to a ground bus bar, if installed, or to the motor itself, or to the ground terminal on Bank 2.

It is sort of a guess on the ground, but to point to Bank 1 seems plausible, if not probable.

 

[jonfreeman]

Well -

I went down friday, and checked the following items:
- Battery fluids - Good
- Battery charge - Good both banks (dockside charger was on for 5 days...)
- Connections at battery - did some cleaning and tightening, but no sign of arcing or heat damage.
- Connectors at selector switch - these SEEMED looser than appropriate, so tightened them.

I started the engine on the suspect bank, and all appears normal (votmeter on, oil light OFF). Since I didn't find any OBVIOUS issues, I am still gonna keep looking. It would be great if the tightening of nuts is all that was required, but...

next up -

- Alternator connections
- Engine grounds

Jon Freeman
C-310 "Summer Sojourn"
Tacoma/Seattle