Battery Charger Bad?

[Rick Berman]

Hey y'all - I've got a Promatic 30-3, probably around 10 years old (it came with the boat so I'm guessing).  It has worked like a charm for the 5 years I've owned my 87' C34.   I arrived for my every-other weekend check, and found no DC power.  Here are the symtoms:
-the house bank (2 group 24s) are down to 6.48 volts
- the charger had no red light
- I turned off the AC for 3 min, then powered it back on - red light came on but still no output (still reading 6.48 at the Promatic terminals (thinking I'm just reading the charge back from the batteries).
- the fuse inside the promatic is ok
-there appears to be no in-line DC fuse (something I will correct).
-the start batteries (another 2 group 24s) are at 12.5 v, but when I tried to start the engines (thinking I could use the alternator to charge the house batteries, the power to heat the glow plugs must have blown a fuse somewhere (not sure where at this point) because I have no power to the ignition. The battery selector was pointing to "start".

Questions:
1.  Is there any other solution to this problem that is logical other than a bad charger?
2.  What might have caused the no power at the ignition if I have 12.5 volts - is there a starting fuse?  if so, where?
3.  Assuming I have to replace the charger, I'm thinking about a Promariner Pronautic 12-15P.  Why 15 instead of 30?  because I only have radio/CD and lights - no refrig or other power requirement.  Thoughts on this?



as always - Gracias!

[Ken Juul]

There is a fuse in the start circuit.  It is buried in the rats nest of wires behind the alternator, it is a know problem, might be the holder/corrosion/etc and not the fuse.

Try cycling the battery charger on off switch, might be passing enough power to light the red light but not power the unit.  If nothing was on...curious why the house bank was drained?  Perhaps the charger has an internal short that caused it? 

How is the start battery charged?  If through an echo or acr then it would be ok, if direct wired to charger why didn't they die too.

Can't help with the new charger choice....I'm very happy with my TrueCharge 20.

[noworries]

How old are the batteries?

My boat had an old lewco charger (25lb beast).  The boat had sat for a while.  When I tried charging the batteries one failed (rotten eggs heated up leaking fluid).  I was reading low voltage on the batteries even though the charger was plugged in.  Removing the bad battery fixed it.

I would try isolating the charger to each battery individually to make sure the issue is with the charger and not the batteries.

I now have all new batteries and new Mastercharge charger.  Haven't had any issues... my only comment about the mastercharge is it has a fan that can be kind of noisy.  Other then that it's been good so far.

[Ted Pounds]

You need to get those batteries recharged ASAP!  Bring a charger from home of borrow a friends.  At the voltage you mention they may be beyond saving already.  Also a possibility that battery went bad first then killed charger?  Good luck.

[Stu Jackson]

There is a fuse in the start circuit.  It is buried in the rats nest of wires behind the alternator, it is a know problem, might be the holder/corrosion/etc and not the fuse.

Read replies #15 & #24 on page 2 of the Critical Upgrades topic.