Front clearance lights out. Please help.

[tommymsw]

ALL of the 5 front clearance lights are out on my 2000 Adventurer 35B. ALL of the other lights work (rear clearance and side markers) so I am guessing it is not a fuse (although I have no idea).

Some people have said that if ONE light is out, then they will ALL go out, but if they are on the same fuse, I would think then ALL the lights would go out. Not just the front.

I checked the housing on each light and while there was some moisture in some of the lenses, the wiring looked to be perfect.

Any points in the right direction would be most welcomed.

[l1v3fr33ord1]

tommymsw-

By the brochure, your coach is built on a Ford chassis.

Fuse #6 is the BJB (Battery Junction Box), which is under the hood, is the Ford fuse that feed the "parking lights." (See this link, page 45.) You should pull that fuse and confirm that all the "parking lights," including the clearance lights, stop working.

Once you've run that test (and put fuse #6 back), you should look at the Winnebago drawings for your coach (link here). The last sheet of the "Auto Lamps Wiring Diagram" (link here) says that the front clearance lights share a common +12V and ground. If you trace the +12V feed wire ("MM") you'll see it supplies the other lamps on the coach (Note: I believe there is a mistake in the diagram.) From that information, and the fact that your other lamps are working, the logical conclusion is that the ground for the front clearance lights is faulty.

[tommymsw]

Originally Posted by l1v3fr33ord1

tommymsw-

By the brochure, your coach is built on a Ford chassis.

Fuse #6 is the BJB (Battery Junction Box), which is under the hood, is the Ford fuse that feed the "parking lights." (See this link, page 45.) You should pull that fuse and confirm that all the "parking lights," including the clearance lights, stop working.

Once you've run that test (and put fuse #6 back), you should look at the Winnebago drawings for your coach (link here). The last sheet of the "Auto Lamps Wiring Diagram" (link here) says that the front clearance lights share a common +12V and ground. If you trace the +12V feed wire ("MM") you'll see it supplies the other lamps on the coach (Note: I believe there is a mistake in the diagram.) From that information, and the fact that your other lamps are working, the logical conclusion is that the ground for the front clearance lights is faulty.

WOW! That was an extremely thorough answer! Thank you!

As I am not great at reading wiring diagrams... Would that mean that having ONE bad bulb WOULD make them all not work?

I know that ALL the marker lights are not connected as I was missing the driver/front marker all together (bulb missing) and the lights (minus the top/front) worked.

NOTE: I did replace all the front bulbs with LED bulbs hoping to fix the problem, but I forgot LED bulbs are polarized and they are unlikely all correct. If it is true that NONE will work if ONE is in wrong, I will mark them and reinsert them correctly.

[l1v3fr33ord1]

tommymsw-

By the diagram, the front clearance bulbs are connected in parallel. When they are working as designed, removing a bulb should not affect any of the others.

As the 12V "MM" wire also supplies lights other than the front clearance, but the ground for the front clearance lights is on a single wire ("MS"), there are two logical hypotheses:

1) As I said before, the ground is faulty, and/or
2) The connector that carries 12V and ground to the front clearance lights has come loose

The diagram says the 2-pin connector may be found behind the front TV. If you can find that connector you can put a voltmeter on it and see if 12V and ground are intact. Alternatively, if you find the ground, you can supply a temporary ground to see if that is the problem.

[Jbmsr]

Originally Posted by tommymsw

ALL of the 5 front clearance lights are out on my 2000 Adventurer 35B. ALL of the other lights work (rear clearance and side markers) so I am guessing it is not a fuse (although I have no idea).

Some people have said that if ONE light is out, then they will ALL go out, but if they are on the same fuse, I would think then ALL the lights would go out. Not just the front.

I checked the housing on each light and while there was some moisture in some of the lenses, the wiring looked to be perfect.

Any points in the right direction would be most welcomed.

Tommy
I would turn the clearance lights on and use an extended reach test light to test the two clearance light source wires.

If no ground is present, temperaraly add one. If the other clearance light come on I would add a new ground wire from a solid source.

If no positive is present and you have checked all possible fuses, you will need to trace the non negative wire (which should be positive)down to the switch. It usually runs down behind the drivers side window post trim.
Jesse

[tommymsw]

So I ripped the front TV out to get access to the front clearance lights. The access is fantastic! I found a "clip" where two wires plug into the 2 wires that feed the lights. I unplugged the clip and found no power coming from the lead wires. They look fine as far as I can trace them (they disappear behind the driver side top storage compartment.)

So... As it seems to be just a single 2 wire line that plugs into the lights, is it possible there is a fuse JUST for that set of wires? Or... Can anybody tell me where those wires meet at the next junction that has easy access? (I can't read the wire diagrams that well).

i can't imagine what would have caused this one set of wires to fail other than a fuse or maybe a disconnect somewhere? There is another set of 2 wires that are bundled with this set that lead to the "map light" between the passenger and driver... This wire seems also to not be working.

For the record, when I set my meter on (2) as opposed to (20), I did get .005 on the wire when I had the lights on and .002 when I turned them off. The "map light" is also not "not working", it is just SUPER dim.

[l1v3fr33ord1]

tommymsw-

Did you perform the test I described in post #2, which was on Fuse #6 in the Power Distribution Box under the hood?

[tommymsw]

Originally Posted by l1v3fr33ord1

tommymsw-

Did you perform the test I described in post #2, which was on Fuse #6 in the Power Distribution Box under the hood?

Before I made the post I pulled every fuse in the power distribution box (including #6) and they all appeared fine. I will have another look at it when the weather permits. I am in NH and we have been dealing with "second winter". Been doing what I could from inside the last few days

If I have to, I will plug a 9v battery into them to get them to work when I take it to get inspected. I can not for the life of me figure out how it could be dangerous to not have them working. Not in 2018 anyway.

[l1v3fr33ord1]

The test I suggested is a bit different than checking to see if the fuse is intact. It involves seeing if ALL the clearance lights go out when Fuse #6 is removed.

[70ChevelleSS]

As a note, removing one light will not make the others go out. They are not connected in series. They are 12v lights, if you connected 5 in series then each bulb would only get 2.4v.

[tommymsw]

Originally Posted by l1v3fr33ord1

The test I suggested is a bit different than checking to see if the fuse is intact. It involves seeing if ALL the clearance lights go out when Fuse #6 is removed.

It was nice out today and I tried this. When #6 is pulled ALL the clearance and marker lights go out. I notice on the wire going to the top clearance, I get .5V when I turn on the lights, and 0 with them off. I was just going to splice the map light power into the clearance lights, but they also are not fully powered. They must be connected somewhere.

The map light also seems to get 1.5v on and 0 when I turn the lights off. If I pull on the bundle of wires (map light and clearance all tied together), I can get the volts to jump up to over 3.

Now I just need to trace the wires and see where the problem is. Hopefully it is some place accessible.

[tommymsw]

SOLVED!

Thank you all, you saved me a ton of time and helped me narrow the problem down.

For those interested:
I traced the wires down the driver's side behind an easily removable panel running down the windshield. Where the side met the dash (metal), it had rubbed together and frayed the wires. Glad I found it, they were all melted. I cut the bad part of the wires out and spliced in new wires. Working great now.

[l1v3fr33ord1]

tommymsw-

Glad to hear you found and fixed the problem.

[Jbmsr]

Tommy
Great work!
You save much downtime and money. Also you will help others with the same problem who see this.
Thank you
Jesse