Community Forums

Gadget Man · 07-15-2015, 07:38 PM

I'm experiencing a 12V power failure. I noticed that my driver's side headlamp quit working. The bulb is fine, there is no power going to the driver side headlight harness, even though the passenger side has power. A check of the fuse panel revealed a breaker for each headlight. I swapped the breakers - no change.

Looking under the front access door (hood), I discovered that the large 12V lug shown in the below photo is also dead. This lug is always hot. I can not for the life of me find a fuse or breaker for this lug.

I tried disconnecting the chassis batteries for a spell to see if it would somehow reset, but no luck.

Any suggestions?

Craig

dpinvidic · 07-15-2015, 08:01 PM

Look for a big fuse in the battery compartment. 200 or 300 amps. Around where the busbars are.
Do you have a disconnect switch, it might be bad.

Dan

Gadget Man · 07-15-2015, 08:44 PM

Quote:

Originally Posted by dpinvidic

Look for a big fuse in the battery compartment. 200 or 300 amps. Around where the busbars are.
Do you have a disconnect switch, it might be bad.

Dan,

Thanks for the reply.

I forgot to mention that I tried the disconnect switch earlier. It switched off the rest of the coach but failed to re-energize the main lug in the original photo.

The issue for some weird reason is getting worse. Yesterday I had power to the ignition, today I don't.

I went to the battery compartment and removed the fuse panel cover. There is a lot of wiring and a number of small amperage fuses inside. There is a large breaker, but I have not had good luck with circuit boards, so I am afraid to touch anything.

The positive battery cable on the back wall in the top of the below photo is also dead. it is usually hot - I believe it routes to the lug shown in the original photo.

Craig

superk · 07-15-2015, 10:43 PM

bottom left corner of the BCC (that fuse box) there should be two small black boxes, they are breakers. check for one pushed out.

Gadget Man · 07-16-2015, 07:25 AM

Quote:

Originally Posted by superk

bottom left corner of the BCC (that fuse box) there should be two small black boxes, they are breakers. check for one pushed out.

I just checked both breakers - neither one was tripped but neither one has power either so it must be something wired ahead of them.

Thanks anyway.

Craig

superk · 07-18-2015, 07:17 PM

I dont have a wiring diagram, so I dont know if a disconnect switch would cut power before or after those breakers. Do you have power to the disconnect solenoids? It might be a dead solenoid. I believe the disconnect solenoids are behind the circuit board in the BCC. The large solenoid you see to the right I believe is the one which bridges the two sets of batteries together. Perhaps check all 3.

When you engage your disconnect switches, do you hear them 'clunk' as you turn them on/off?

My aux start solenoid needs to be replaced. 1/4 of the time I engage it, it actually gives power. I hear it clunk but the inside must be scored too badly to make a connection.

Gadget Man · 07-18-2015, 07:54 PM

Quote:

Originally Posted by superk

I dont have a wiring diagram, so I dont know if a disconnect switch would cut power before or after those breakers. Do you have power to the disconnect solenoids? It might be a dead solenoid. I believe the disconnect solenoids are behind the circuit board in the BCC. The large solenoid you see to the right I believe is the one which bridges the two sets of batteries together. Perhaps check all 3.

When you engage your disconnect switches, do you hear them 'clunk' as you turn them on/off?

superk,

I did some more diagnosing yesterday and I believe it is in fact the engine battery disconnect switch and/or solenoid as you suggested. The solenoid makes no noise like it normally does when I hit the switch. I of course have no idea why this would disable one headlight, but we will see. I have an extended warranty so I'm not going to go any further. I was hoping it was something simple that I could do myself, but it's a lot more complicated. I have a mobile RV repair tech that I depend on but he is in vacation right now. I told him what I found and sent him a text with a photo of the BCC. He said the same as you, the solenoid is behind the circuit boards. He'll be here next Friday to work in it. I'm just glad this happened at home and not while in a CG!

Thanks for the help.

Craig

Old Bounder · 07-18-2015, 07:59 PM

The battery disconnect solenoid contacts are the only thing between those breakers and battery. The disconnect will not be the problem with your headlight.

superk · 07-18-2015, 11:06 PM

Quote:

Originally Posted by Old Bounder

The battery disconnect solenoid contacts are the only thing between those breakers and battery. The disconnect will not be the problem with your headlight.

As Old Bounder mentioned, the bcc has nothing to do with headlight. I suspect coincidence there. Maybe take a few minutes to search around for loose wires, or bad connections/grounds?

However, as you said, if you have the extended warranty, and arent stuck somewhere needing to get out, waiting for the tech would be the simplest and possibly safest bet.

Please do post back and let us know what the problem ended up being!

Gadget Man · 07-19-2015, 09:04 AM

Quote:

Originally Posted by superk

As Old Bounder mentioned, the bcc has nothing to do with headlight. I suspect coincidence there. Maybe take a few minutes to search around for loose wires, or bad connections/grounds?.......Please do post back and let us know what the problem ended up being!

I agree that the two should have nothing to do with each other, but it is odd that they both happened to go out at the same time. Even more odd that it's only the driver side headlight.

I'll keep you posted.

Craig

Old Bounder · 07-19-2015, 10:51 AM

Quote:

Originally Posted by Gadget Man

I agree that the two should have nothing to do with each other, but it is odd that they both happened to go out at the same time. Even more odd that it's only the driver side headlight.
I'll keep you posted.Craig

The headlight problem is a chassis builder problem. The BCC was added by Fleetwood. Absolutely NO connection what so ever.

Gadget Man · 07-21-2015, 05:19 PM

My mobile RV tech was able to squeeze me in today. It took him about an hour to locate the problem.

Examining the BCC, he found one blown fuse. Oddly, the fuse was for my leveling jacks. This of course didn't fix my ignition or battery disconnect issue. Armed with a wiring diagram that I got from Freightliner, he found two blown ignition fuses in the spare tire compartment, at the right rear of the coach (shown below). Replacing these fuses restored power to the ignition and corrected the battery disconnect issues. While I am still wondering what caused all of these fuses to blow simultaneously (my tech had no idea), I am glad to be up and running again. Oh yeah, my headlight works again as well...go figure!

Thanks for the help.

Craig