12 V electrical problem

[jmttech]

Hello all!
I have a 2009 Freedom Vision 3150 DS Class A motorhome. I believe it is the same as a Coachmen Mirada. The chassis is Ford F-53 and the manufacturer was, according to the VIN, Coachmen... However, it is/was "rebranded" by Camping World.

To the problem:
I was getting ready to make a small trip and when I started her up, the following failed to work:
Remote control mirrors,
Camera system was dead,
Cigarette lighter sockets (accessory outlets) were dead,
auxiliary dash fans were dead.
Map lights, radio, lights all worked. So far as I can tell, all "house battery" devices are working.

There are two fuse boxes to the left of the brake pedal on the drivers side of the firewall. The topmost (and largest one) appears to have power at all fuses and fuses check OK there.

The lower fuse box (consisting of 4 banks of 4 fuses) only has power to the lowest bank. The other three banks appear to be dead.

The main distribution box accessed from under the front engine cowling seems to have all fuses operational. I say seems because I did not physically remove the fuses to check, but used a continuity probe across the fuses. This may have been a mistake, but man there are a whole butt-load of fuses in this thing!

I did not check all the relays cubes as I am not sure if that needs to be don, I'm looking for input from this venerable group of more experienced RVers.

Any thoughts or ideas would be greatly appreciated. I really don't want to take it to the shop if I can avoid it. We are retired and income is finite.

Thanks in advance to all who may have input or experienced a similar problem.

[jmttech]

As far as tools go (in response to Mountainair) I have VOM and test light (probe).

Good idea about the K5 relay from Bud OnaQuest and Bud. I will check that and the fuse 19 enablethen refers to.

[jmttech]

Thanks for the suggestions, I will check them in the morning. I am assuming that the "black cubes" I referred to are in fact relays. I'm assuming this provides isolation from the chassis cabling harness. So far I have not seen any specific documentation defining what the various relays control.

Good point about probing both ends of the fuses though. No short cuts recommended LOL.

[enblethen]

My Pace Arrow has a large Ford style relay acting as the ignition relay. It receives it power through the solid state circuit board.
My drawing shows it gets it control power from fuse 19 in battery control center.
Yes, my ignition relay has nothing to do with starting the rig.

[OnaQuest]

The ignition relay within the BCC that Bud is referring to is NOT the Ignition (start solenoid), but it is activated with the ignition signal. It does control things like the mirrors, backup camera, dash fans and levelers. The small relay is mounted on the BCC board and is relay K5. There may just be a group of blown fuses or the connector from the BCC board to those circuits may be loose. However, that's the only place all those symptoms have in common.

Not sure why Bud mentioned the charge relay, as that is a totally separate function of the BCC. The charge relay closes anytime the charging voltage reaches 13.2vdc or greater, it has NO real bearing on whether the batteries are fully charged yet, of not.

[enblethen]

No the chassis HVAC on mine anyway, is powered off the fuse block supplied by chassis. The charge relay on mine does not come on unless the engine has brought chassis batteries up to a given level then energizes.

[wolfe10]

On edit after reading Bud's post immediately below:

I was incorrect-- assumed that the ignition solenoid also controlled all features that are on only with ignition on (like the dash HVAC fan).

Evidently on the OP's chassis, that is not correct. Sorry for the misdirection.

[enblethen]

Locate battery control center and find the ignition relay. It powers the rig's manufacturer's installed accessories.

[Tinstar]

Probe all the fuses with a test light. Ground the wire and probe the other end of the fuses. Check all the "box" fuses (I guess you're talking about resetable fuses). Those are how much of my dash electronics are powered. I'll bet you'll find something not getting power to the other side of a fuse somewhere.

[MountainAir05]

do you have a digital volt/ohm meter, or tone meter.

[1492]

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