Electrical conundrums: dead alternator (?), house battery... - Page 2

**daveb** · 06-16-2013, 12:38 AM

For me it was a PITA but I didn't have the right tool to put on the belt. Took 2 of us about 2 hours but we never took the batteries out or disconnected them.

Zeta · 06-16-2013, 02:13 AM

I'm installing an HO alternator in my rig. It isn't fun, but once I bought the NAPA serpentine belt tool, it made it much easier. I'm also running a size 0 cable from the alt to the starter to, hopefully, get all $600 worth.

I disconnected the batteries and, weirdly, the winch which seemed to be acting as a ground as I had power to the alt even with all three batteries disconnected.

The next one I do will be a POC.

Z

dparkwy · 06-17-2013, 07:39 AM

Z.......re: "the next one" might be at the Gros Ventre Campground. New 185A alternator scheduled to arrive tomorrow along with a serp belt tool. Knock on wood I'll be able to get it in by myself. Otherwise I might be looking you up in Jackson this weekend.

dparkwy · 06-18-2013, 07:39 AM

Well, it seems like the root cause was a bad stock alternator. I replaced it with a 185A version from Nations Alternator and, knock on wood, all seems well now. De-tensioning the serp belt wasn't too bad with the right tool, but I did attack it from the underside which was easier.

The symptoms were caused by a bad alternator and also the Blue Sea ACR (9112) wiring. The ACR was wired to connect the battery banks whenever the engine was running. Thus I was unknowingly drawing down my house battery. I changed the wiring so it doesn't default to that state, but will still automatically charge bi-directionally.

Thanks, JoeH, Scalf77, and Z for your help/input. Very much appreciated....

**daveb** · 06-18-2013, 01:22 PM

Quote:

Originally Posted by dparkwy

The ACR was wired to connect the battery banks whenever the engine was running. Thus I was unknowingly drawing down my house battery. I changed the wiring so it doesn't default to that state, but will still automatically charge bi-directionally.

??? I'm not understanding that. Can you explain that feature?
I have always had the ACR close when the engine runs...that is how it charges the house system. I did disconnect the jump assist starting feature so I know when I have a starting battery issue. My ACR simply stays connected until the one or the other battery systems falls to 12.8vDC which is normal. As soon as either side see's a voltage rise to about 13.3, (such as when the engine starts and the alternator is outputting) the separator closes. If I didn't have that set that way the solar would not keep both battery systems up while the van sits.

dparkwy · 06-18-2013, 03:24 PM

The wiring was the difference between manual control mode vs. auto mode. Mine *was* wired in manual control mode. The (orange) control wire on my 9112 was connected to the run circuit, so whenever the engine was on, the relay closed. The control wire just has to have more than 9v to close the relay. I disconnected the control wire so now it automatically charges bi-directionally. This is probably how yours is connected?

Having the control wire connected in manual mode was not favorable when the alternator went bad. There was enough voltage to keep the relay closed and the systems connected, but I ended up getting both battery banks to a pretty low voltage state just by driving it and not quite realizing what was going on.

Manual control mode: battery banks only connected when the engine run circuit has greater than 9v, regardless of if your alternator is working. Also, solar would only be good for charging one bank with the engine off, since the relay would be open. Keeps the systems separate when the engine is off.

Auto control mode: battery banks connected based on voltage sensing; engine run circuit does not need to be on. Can charge your engine batteries via shore power b/c the relay will activate.

I suppose there are pros/cons to each mode....hope this helped or was somewhat clear!

**daveb** · 06-18-2013, 07:46 PM

Mine, a 7622 with remote is configured to close when either side of the ACR see's a voltage of 13.2 or higher. It opens at 12.8v. I know there is start circuit that momentarily closes the relay for assist starting. I don't recall a constant closed setting but there's probably one on there somewhere. I actually have mine hooked kind of opposite...even if the relay is closed because of the solar, when I turn on the ignition the ACR relay cuts out and separates during the start. After 30 seconds the relay monitors the voltage and if it senses a charge voltage (13.2+) it closes. Anytime either side drops 12.8 it opens.
The only problem I have with that setup is if I leave the shore charge on and one of the starting batteries goes bad. The charger will continue to pump all it can into the bad starting battery. Not really anything I can do about that except monitor the charge. I have 3 ways to monitor but have found when parameters start to change, it's time to look for problems. I can usually see a problem with failing batteries or an alternator several days prior to real trouble now days. As far as the house batteries, I can tell months in advance when there is a problem with them. Shorts can happen at anytime and you have to take that as it comes.

Glad you got your rig back together...loosing batteries can be expensive.

Scalf77 · 06-18-2013, 09:10 PM

It looks like the Blue Sea 9112 was pretty much a drop in for the original Surepower 1315 that dparkwy's previous owner had replaced. They don't reference it as start assist but they do have an input to switch to 12 volts to force it on (manual mode). In his case his original assumption was that the alternator was going bad but he could not understand how the house batteries were getting depleted also. He assumed hat 9112 was disconnecting at the 12.6 volts or never connected at 13.6 volts. Well I assume that the original sportsmobile wiring was wrong and the wire that was their for the start assist was not connected to the ignition start circuit, but instead in then run circuit. The run circuit provides 12 volts while the key is in run, so this forced the Blue Sea 9112 to be closed as long as the run circuit was above 9.0 volts. If connected to the start circuit it would only provide 12 volts while the key was in start. So this just confused the situation and made it harder for dparkwy to convince himself that it was the alternator, which is what he was thinking. IMO if you have a 2004 SMB out of Fresno, you might want to check to see if yours is wired correct, you really have to check because it will pretty much look like it is working, the difference is when the van is running the voltage comparator circuits are overridden by the manual mode.
greg