Author Topic: 12V Power Failure  (Read 4731 times)

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Offline Gadget Man

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12V Power Failure
« on: July 15, 2015, 06:45:28 PM »
I have an '05 Fleetwood Providence with a Cat C7, atop a Freightliner XC chassis. 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 firewall 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
2005 Fleetwood Providence 39J
Cat C7 350, MP-8 Tuner
Freightliner XC Chassis

Offline Brett Wolfe

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Re: 12V Power Failure
« Reply #1 on: July 16, 2015, 05:03:25 AM »
Craig,

I don't know the wiring on your coach, but given the gauge of the wire, there is likely a very large fuse near the battery end of the wire. Possibly a high-amp breaker, but more likely a large fuse.

Brett

Offline ziggyh

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Re: 12V Power Failure
« Reply #2 on: July 16, 2015, 09:20:55 AM »
Does the breaker for the nonworking headlamp get hot or click when it is removed and reinserted after a few seconds when the headlamps are turned on.
ZiggyH

2007 Revolution LE
C9

Offline Gadget Man

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Re: 12V Power Failure
« Reply #3 on: July 16, 2015, 02:59:16 PM »
I don't know the wiring on your coach, but given the gauge of the wire, there is likely a very large fuse near the battery end of the wire. Possibly a high-amp breaker, but more likely a large fuse.
I've spent two days trying to locate a large fuse or breaker with no luck. Disconnecting and reconnecting the engine batteries made matters worse as I have now also lost my ignition. I have a mobile tech coming to the house tomorrow.


Does the breaker for the nonworking headlamp get hot or click when it is removed and reinserted after a few seconds when the headlamps are turned on.
No, no sound whatsoever.

Frustrating!  :o

Craig
2005 Fleetwood Providence 39J
Cat C7 350, MP-8 Tuner
Freightliner XC Chassis

Offline David.e.atherton

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Re: 12V Power Failure
« Reply #4 on: July 22, 2015, 05:20:36 AM »
Craig, looking for a breaker or fuse because you have lost 12 volt power. I would suggest
power wire that size looking for a open at the ground, dirty or loose connection. Sometimes
possible look around your start boost switch off house batteries. See what happens when you
apply the boost start switch and check for power at above wire. Dave At herton retires Cat Mechanic.

Offline ziggyh

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Re: 12V Power Failure
« Reply #5 on: July 23, 2015, 02:14:01 PM »

looking at the size of the wire I would think that it feeds more than just a few circuits, and having it get hot and no power I would suspect that there is a loose connection on the other side of the post.   Electrical connections only get hot when there is current flowing and some resistance. If you lost your ignition after disconnecting the batteries, I would recheck my connections that were removed, perhaps something was missed in the process creating an additional problem.

Fleetwood has ben very good with providing wiring diagrams when ever I have e-mailed them for ones on my coach as well as Spartan chassis. I would think Freightliner would be as well.  The diagrams are one of the best tools one could have when troubleshooting. 

Good luck, let us know what you find.
ZiggyH

2007 Revolution LE
C9