Charging while driving...not

[hdossett]

My coach batteries have never charged while driving. Lots of reasons it did not bother me before, but now it does. Go figure! Have searched forums without success.


Attached photo is my Battery control center board. Where should I start?

Thanks, Harold
P.S. I love it when the photos work

[Richard S.]

Do you have the drawing for the BCC.

[hdossett]

Quote:

Originally Posted by Richard S. Do you have the drawing for the BCC.

Yes

[Richard S.]

A good place to start would be at the interconnect solenoid

[Richard S.]

Got this info off another National RV owners site.

[hdossett]

Richard,

I think the solenoid is working, I have used it a number of time to boost start the engine and also the gen set. I was assuming it would be the same one. Checked this morning, with engine running, 14V on one side and 12.5v on the other side. (just went out and checked, it is working (the one on the left, behind the board))

What about the relay (vf7-11f12 in middle of the board) it is a rated for 70 amps. Do you know if it is related to the interconnect circuit?



Thanks for any info

Harold

[Capt. Flipper]

My vote would still be for the interconnect solenoid. This is a particularly troublesome part on many RVs. It may work fine for boost start but fails to complete the circuit for battery charging due to contact oxidation preventing current flow at lower currents.

When this solenoid is energized such as when on shore power or with the engine running it should be warm to the touch. If it is warm, the voltage on one side should be within .1 V of the other side. Put your voltmeter across the 2 large posts (accessed easily via the hex head bolts on the circuit board). The voltage should be .1 V or less. If it is higher, gently tap the solenoid with a screwdriver handle or some other non-metallic tool. If the voltage changes, replace the solenoid.

On the other hand, if the solenoid is cold to the touch after 10 minutes of shore power or engine idling, there could be a problem on the circuit board or wiring that supplies actuating power to the solenoid pull-in coil.

[Richard S.]

I don't know the answer about the relay, a call to RV Custom Products might be the best way to go.

14000 Anson Ave
Santa Fe Springs, CA,
90670-5202
Phone: 562-921-8353
Fax: 562-404-7652

[hdossett]

A little more probing and this is what I found:


Initial reading
across Interconnect solenoid coil 0 volts
blk to gnd 0 volts
Yel to gnd 0 volts

Engine Running 3 minutes 0 volts
blk to gnd 0 volts
yel to gnd 0 volts

Shore power and charger blk to gnd 0 volts
Yel to gnd 0 volts

Booster Switch Active blk to gnd 15.0 volts


This rules sout the solenoid for me, The One (1) amp fuse is good, That leaves the comparator circuit or the a relay if there is one in this circuit!

Any other suggestions?
Any one?

Thanks

[Capt. Flipper]

I agree. From your measurements, it sounds like interconnect solenoid K3 is OK. The relay on the board is probably K1 and controls ignition switched circuits. If so, it is not involved. That leaves only the comparator circuit on the board or it's associated wiring. I'm a little confused by your measurement with the boost start switch depressed. You say 15V blk to gnd. Circuit diagram shows yel being the hot wire to solenoid coil. I assume you hear solenoid pull in when pushing the button. If you are confident of your measurements, the board needs to be replaced or repaired.

Several years ago I removed my circuit board and created a schematic for the comparator circuit for diagnostic purposes. As you probably know, using the boost button bypasses the comparator and energizes the solenoid K3 directly. The circuit is not rocket science but can be hard to troubleshoot without a schematic. The comparator circuit is located in the lower left corner of the large circuit board. There are several surface mount components and a small calibration potentiometer. Do not adjust it. It controls the pull-in and drop-out voltages. Look over this area with a magnifiying glass for signs of burned components or physical damage. It's possible for a skilled electronics tech to repair some items on the board if you find the right kind of person (hobbyist). Otherwise, you're in for an expensive part from RV Custom Electronics.

Good Luck

[hdossett]

just a follow up, I am examining the PC board with a Macro lens, better than a magnifying glass! Only thing I saw that stood out is the Q43, looks like it has been replaced, factory repair before shipping, or R/R after shipping?

I did a lot of PCB repair about 30 years ago with IBM on their new $100K ink jet printer! Surface mount was up and coming then, so did not do much of that. Just need sharp tweezers and a steady hand, I guess. Trouble shooting skills were limited but had a lot of guys around that knew more than me.

[baustin]

So glad to see someone mention the "1 Amp Fuse" Have not been able to find a sheet for my RV Custom Products 12V PDC Rev 4 This fuse is blown, but do not know what it does. Fuse is not available at Auto supplies or Radio Shacks, and discovered over weekend, so will have to hunt on a weekday. But please, someone tell me what it does.
Thanks,
Bruce

[garym114]

The one amp fuse is for the interconnect solenoid circitury. Without it the solenoid will not work. I had my local auto parts store order me 4 of them.
The solenoid should close when either battery system gets to 13.2 volts connecting the two battery systems. It should open when either gets to 12.8 volts.

[04sterling]

The RCP power board is a bit mysterious at first glance, the info posted here will help you sort that out. (Nice job guys) if you need to get new breakers with manual reset (black button on the side) go to an electronics store to get replacements, your local auto parts guys wont have the breakers with the manual reset. I matched the amperage printed on the side of the breakers and changed them all. I bought a few spares because they were a whopping $5.99 each and hard to find in a small town. I replaced my solenoid too, found on online for $30 replaced it to be sure I wouldn’t have to take it apart again soon. Take some pictures and mark your cables, if you leave for lunch and return a week later it may not all look the same. You can get breakers with manual or auto reset. I recommend continuing to use the manual reset, but in my case I used the auto reset (no black button on the side) just for the one that nuisance trips on my coach shore charge circuit, now the problem is now gone no more dead house battteries. I have been using it this way for a year+ and all is well. Since it is a pain in the behind to take out the board I suggest replacing all the relays and maybe the soleniod but that depends on your tollerance for sticking your head in the little bay to bolt it back up!.