Volvo battery alarm

[Scrib]

Now we’re getting somewhere, love learning new stuff. Thx for sharing.

Capt, I’ll try the on/off fool the system strategy. If it works that would be great even if it only turns the alarm off and I still need a new alternator. The damn alarm is very loud & very annoying. I’ve got it damped down with some tape over it now.

Genius, thanks for the clear explanation. I get it. So I’m going to circle back to one of my follow-up questions which relates to your explanation. I’m thinking of going to 100A or better from the 50A today. With a higher output alternator, might this alleviate the need for a more sophisticated regulator as it should more easily keep up with re-charging demand.

 

[captjohn]

Now we’re getting somewhere, love learning new stuff. Thx for sharing.

Capt, I’ll try the on/off fool the system strategy. If it works that would be great even if it only turns the alarm off and I still need a new alternator. The damn alarm is very loud & very annoying. I’ve got it damped down with some tape over it now.

Genius, thanks for the clear explanation. I get it. So I’m going to circle back to one of my follow-up questions which relates to your explanation. I’m thinking of going to 100A or better from the 50A today. With a higher output alternator, might this alleviate the need for a more sophisticated regulator as it should more easily keep up with re-charging demand.

In my case it doesn't just make the alarm go off, it corrects the low voltage problem, until the next time I start the engine.

 

[skiprocks]

I have a 2002 TAMD31P and I get this alarm now and then. For me it's come down to 1 of 3 things in order of frequency
1. Most often I leave the 120v battery charger on when I start the engine. The "why" doesn't make sense to me, but the alarm goes off when the charger is energized and I start the main.
2. A couple of times a year I need to tighten the drive belt on the alternator. I've never had an drive belt loosen up this often and I haven't determined why.
3. Alternator failed - once

 

[Scrib]

Frustrating afternoon. Installed a new alternator. A little bigger @ 94A than the original. Install no big deal, took about an hour. Result? No change. Battery alarm still screaming and now the voltmeter only reading about 11V, maybe a little less. I was frustrated so went for a little boat ride instead of trying to diagnose the charging flow. I’ll do that tomorrow. Maybe a bum new alternator? Maybe a bad wire somewhere between the alternator and the alarm and/or voltmeter? Time will tell I guess

 

[Scrib]

Think I found it - alternator fuse. It looks like it’s been burned for a while which answers the question why the alarm went off during sea trial last fall. It burned out pretty hot, melted the plastic around where it mounts in the wiring box in the engine. Gonna have to create a new mounting method.

 

[Capt-Pete]

Wow great find! Where exactly is the alternator fuse? I’ve had a similar experience with my alternator but resigned to the fact that I’d just live with the alarm issue until haulout and address it over the winter…

 

[Capt-Pete]

Any chance you could take a picture of the fuse location?

 

[Scrib]

Any chance you could take a picture of the fuse location?

It’s on the bottom of the wire connect box which on this engine is in the port side right behind the dipstick. Here’s a pic of the good fuse & the aft side of the burnt fuse and a pic of the burnt fuse & melted holder.
It’s a hard location to get a good pic ‘cause it’s down low about the height of the top of the oil pan. The wires to each side of the fuse come up through the bottom of the box. On this engine one fuse is the alternator but I don’t know what the other fuse is for (yet).

 

[Genius]

Why did the fuse go?

 

[Capt-Pete]

Wow that’s very interesting…. I’m not sure if my engine has a fuse like that but I’m going to check ASAP! A bit crude of a fuse and a little “unprotected” for current to flow through it but I guess it’s ok… My engine is a 61A and I would assume not too much different from the 60B you have. I’d be ecstatic to know that my issue is just a fuse. I’ve been dreading the task of hunting down a little wire break somewhere that controls the alarms etc… thanks for the update and pics!!

 

[Scrib]

Why did the fuse go?

I have no idea but believe it’s been bad since I bought the boat last fall.

 

[Scrib]

Wow that’s very interesting…. I’m not sure if my engine has a fuse like that but I’m going to check ASAP! A bit crude of a fuse and a little “unprotected” for current to flow through it but I guess it’s ok… My engine is a 61A and I would assume not too much different from the 60B you have. I’d be ecstatic to know that my issue is just a fuse. I’ve been dreading the task of hunting down a little wire break somewhere that controls the alarms etc… thanks for the update and pics!!

I put back a 100A fuse (different style) because I installed a 94A alternator. The fuse installation now isn’t as clean but I think sufficient to prevent any shorts. I also bought a 100A individual auxiliary circuit breaker that I might install if I have more trouble with this. Now when I turn the key on an alarm sounds, that didn’t happen before. The voltmeter registers about 12.5-13V when the engines running and a check at the batteries showed about 12.8V going in. I’m going to monitor all this very closely.

 

[fullhouse]

I had that problem this spring. My alternator was bad quick rebuild and it was all set

 

[Scrib]

Quick update. After struggling for the last month to get a good charge to the batteries and ultimately a dead starter battery bank (2 GP31's) I chased the ground wire from the alternator to the electrical connection box on the engine ultimately to the starter. I keep finding things on this boat that do not make me happy ... all the battery cables were replaced sometime recently, all are shiny w/good connections EXCEPT the ground cable to the starter! The starter is a bit rusty as one of the raw water drains empty on the starter (I'll fix that) so the ground terminal was very crusty too. It was reasonably accessible so I pulled it apart, sanded down the connectors, the stud, the nut, and replaced the lock washer. I did the same to the positive cable just 'cause I was there with a wrench & sand paper on hand. There was a 3rd terminal for a small wire that runs to the starter cut-out relay, cleaned up that one too. Lo & behold, after doing that task I was finally getting about 13.8V at the batteries. Unfortunately, the battery warning light still stays on but at least I know the batteries charge when the engine's running.