Another intermittent Volvo Penta battery alarm

[Tim-JS]

Hi, wonder if anyone can help me ?

I've done a search thru previous threads, but have come across info/advice that contradicts what I think I'm seeing.

We have a 2007 Elan 410 which has a Volvo Penta D2-40 engine and 130A Mitsubishi alternator.

Last year, we had no alarms at all.
This year, we have an intermittent alarm, which the control panel is saying is a battery alarm.

The Penta manual says:
"The battery lamp shows if the alternator is not charging or voltage is too high, this can be due to a fault in the electrical system or because the alternator drive belt is slack."

To me, the drive belt seems fine.

I've tried to determine what the problem is by taking voltage readings at the battery, on the B+ from the alternator, and the alternator end of the sensor cable, and i've taken these readings when the alarm is sounding and when it's not sounding, but these didn't reveal anything obvious.

Are there any tests I can do to determine what the problem/fix is ?

Thanks, Tim

 

[Daydream believer]

Totally different Volvo to yours, but the intermittent fault I had was a bad connection on the back of the switch panel. I just worked my way through all the connections & problem solved.

 

[Tim-JS]

Totally different Volvo to yours, but the intermittent fault I had was a bad connection on the back of the switch panel. I just worked my way through all the connections & problem solved.

Hi, thanks for this.

A couple of days ago I found that this is where the other end of the sensor wire is connected, and i found that the connection was indeed loose, which was a bit of a surprise because when I'd been manually taking voltage readings with a multimeter at the alternator end of this wire, the readings were very similar whether the alarm was sounding or was silent.

(From memory...one surprise was that disconnecting the sensor cable from the alternator to check the voltage didn't seem to have any effect on the alarm ie if the alarm was sounding and I disconnected the sensor cable the alarm would continue to sound, and if the alarm wasn't sounding and I disconnected it would remain silent. This surprised me as I expected a consistent reaction from the alarm if there was no sensor cable attached. Now that I've typed this it sounds implausible so wonder if i dreamt this bit. Will double check...)

Anyhow, I was hoping this would fix the prob, but yesterday the alarm came on again.

Did you manually take voltage readings when you had the prob, and if so, was it this that led you to your solution?

Thanks again, Tim