no charging voltage

[peteandpatty01]

Have a four winds hurricane motorhome. Had to replace my 12V house batteries (two in parallel). I checked the voltage at the cables that attach to the batteries and have 0 volts. I expected about 13 volts DC. This would be coming from the converter to keep the batteries charged. I checked the out put of the converter and have 13.6 volts DC. All the 12 volt lights work and the engine battery is fully charged after sitting all winter hooked to shore power. So my questions:
Am I correct in expecting 12 to 13 volts at the cable ends that attach to the house batteries?
Is the circuit from the converter to the batteries fused?
If fused where would it be located?
Thanks for any help you folks are great.
Peter

[peteandpatty01]

Problem solved! to try to find our why everything in the battery compartment was dead I bit the bullet and went under the motorhome to follow wires. Can't believe what I found. The heavy gauge wire that brings the converter voltage to the front of the motorhome was too short, so someone bolted on more wire and taped the joint. The bolt came apart so the wire was open. I will run new wire from the converter to the box in the engine compartment, no splices. Once I rejoined the wires everything works.
Thank you so much for your help. Not a total loss I now have a better understanding how the electrical system works in the motorhome. Learned a lot!

[BFL13]

So the house DC panel does get 13.6 from converter which is good.

But that 12.3 (and 14.4?) from engine battery is unknown whether it can reach the house DC fuse panel if the isolator (the one that lets the house batts start the engine if needed) is set for that.

Which means the house battery disconnect switch did not let that 12.3 through or the isolator didn't.

So we still need to know what is stopping the 13.6 from reaching the house batts and we need to eliminate the 85a thing to see if house batt voltage at least gets past that, if not all the way to the house DC panel. If it gets past that 85a thing, then we are back to that house solenoid that clicks but the light stays on?

What about that post above re a BCC? Is that a BIRD? I have no clue about that side of things, don't have a MH.

[peteandpatty01]

Not sure we are talking the same fuses. I find the 12.3 volts in a fuse box in the engine compartment on the fire wall. Book shows there are 12 fuses there. Book also shows a fuse box by the break peddle, can't find that one but found a fuse box in the side of the bed, not mentioned in the book. This fuse box has 13.6 volts in it. I believe the box by the bed is the box that should be by the break peddle. These fuses distribute DC around the camper...lights, fans, etc, the one on the fire wall seems to be for automotive stuff....turn signals, break lights, etc.
The question; does house battery voltage reach fuse box by bed if all else is disconnected is still valid and will be checked out.

[OldF__t]

Maybe this is related to the Thor Battery Control Center Recall.

[BFL13]

Tried to post earlier but rv.net no go today.

No shore power, set isolator so no engine battery to DC fuses. Install house battery. Is there house battery voltage at the fuses?

Problem is the report that converter is 13.6 but fuses see 12.3 engine battery. (or 14.4 alternator) But thing is the solenoid switch is letting that engine battery through to the DC panel. why no 13.6 at fuses????

Need to see if house battery voltage is reaching DC fuse panel to identify if that 85a thing is the problem. If no battery voltage at fuses then by pass/jumper that 85a thing and see what happens then.

There may even be a problem where you don't see any voltage with no battery, because those wires need to touch as when on the battery. If so, with no battery, then with no battery you have to clamp them together as though on battery posts.

[peteandpatty01]

Took off shore power, ran engine and measured voltage at the fuses got 14.4 VDC. Still no voltage at the terminals of the house batteries. Now trying to get some information from Intellitec Corp. they make the distribution box holding the battery disconnect. Everything seems to point to a bad house battery disconnect solenoid holding the house battery out of the system.

[BFL13]

peteandpatty01 wrote:
To be clear, the new house batteries are NOT attached to the system. I am looking for the charging voltage at the terminals that will attach to the batteries.
I have not looked for voltage with the engine running, but I will.
Sounds like the voltage I see at the fuses comes from the motor battery not the converter. I will disconnect that battery and see if there is still voltage at the fuses.
Not sure how to test the solenoid.

If you see 12.3 from chassis battery at the DC house panel, that means you have closed the "isolator and aux/start relay solenoid" (which I believe is a dash button in a MH) so you should also get alternator charging if the engine were on)

IMO turn that off while trying to isolate the problem here why no converter voltage at the house battery.

Now, since the batteries are not connected, the 85a gizmo should not have battery voltage on one side but should have converter voltage on the other side ASSuming the solenoid for that set of batteries is closed. Since it clicked closed ( but the light stayed on?), and there is no voltage downstream at the 85a thing, that means the solenoid is still open even though it clicked.

However that leaves why not converter voltage 13.6 at the DC dist panel instead of 12.3 motor battery voltage

I am using OnaQuest's drawing of his MH set-up

http://d1.dropbox.com/u/15918372/Inverter%20Feed%203.jpg

[wa8yxm]

THe following are on the suspect list:

Wrong cable.. Only one of those wires will have power on it, the others are power suckers. (or grounds on the negative side).

Blown fuse (Probability low)
Tripped circuit breaker (Probability medium)
Disconnect set in STORE/OFF/DISCONNECTED (probability high)

Bad wire, OR connection.. I'd rate this medium to medium high (connection)

Have had all the above.

[peteandpatty01]

To be clear, the new house batteries are NOT attached to the system. I am looking for the charging voltage at the terminals that will attach to the batteries.
I have not looked for voltage with the engine running, but I will.
Sounds like the voltage I see at the fuses comes from the motor battery not the converter. I will disconnect that battery and see if there is still voltage at the fuses.
Not sure how to test the solenoid.

[BFL13]

If you get no voltage either side of the 85amp breaker/fuse seems to me that one side of it is not seeing battery voltage of 12.x and the other side is not seeing converter voltage of 13.x. So no ground anywhere?

Maybe jumper the 85a thing and see what happens to the battery post voltage

EDIT. you do get 12.3 at the fuses so that must be battery voltage, not converter voltage so it is confusing you get no voltage in places as reported. Are you getting battery voltage at the DC panel? Are the batteries at 12.3 instead of 12.7 as new? If so they should be put on a charger until you can get this converter supply sorted out.

Now that you can hear the solenoid clicking, does that light still stay on? That might mean the solenoid is moving but not making contact.

Do you get battery charging via the alternator / isolator path with the engine running?

Did you put all the wires back on when installing the new batteries? 🙂

No idea what it is exactly, but some threads like this mentioned a BIRD some MHs have. If you have one, is it ok?

[peteandpatty01]

BFL13, I can hear both solenoid open and close as the disconnect switches are turned on and off. I have checked all the fuses I can find, all have 12.3 voles on both sides of the fuse.

[peteandpatty01]

BFL13, There are two disconnect switches at the doorway, one for the house batteries and one for the motor battery. Both have an indicator light to show the batteries are connected. When I disconnect the motor battery the light goes out, when I disconnect the house batteries the light stays on. I will look for the solenoid to see if it has failed "open". There is also a device (black box about 3 inches square) in the positive lead to the house battery. no reset buttons, no way to open it, a current rating of 85 amps. I checked both sides (in lead, out lead) for voltage, both show 0 volts.

[BFL13]

There would be a battery disconnect switch, perhaps at the doorway. It will operate a solenoid switch in the engine compartment that actually is the disconnect switch.

In addition there might be a fuse or DC circuit breaker close to the house batteries on the positive wire.