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Nalle · 09-21-2019, 05:41 AM

Good morning Forumites.

My 2004 Itasca Meridian 34H on a Freightliner Chassis all of a sudden started blowing the 30 amp fuse feeding the Marker/Parking lights.
By my count there are a total of 30 lights and "miles" of combined Freightliner and Winnebago wiring to find a ground fault.
I have individually disconnected and tested all Winnebago wiring to the lights from the Freightliner harness and I am still blowing the fuse - I.e. I believe problem is in the Freightliner harness.

To me, the only thing that can blow the fuse is a ground fault somewhere?? The strange thing is that when I unlock the door with the remote, the Marker Lights will blink, just as the should - with a short to ground, they should not!

However, only front and sides lights will blink - not the rear! With my weak memory, I can not remember if also the rear should blink. ANYONE OUT THERE THAT COULD CHECK IF ALL OR THREE SIDES SHOULD BLINK??? This could maybe provide some guidance as to where to search for my ground fault.

According to the wiring diagrams, there are seven spliced wires for the Marker Light, running all thru the rig. Anyone with a possible ground issue.

Any suggestions or input is much appreciated.

Nalle

richard5933 · 09-21-2019, 05:56 AM

Sounds like you have multiple power sources feeding the lighting circuit. Apparently the circuit feeding it when you use the remote is working. The circuit feeding it from the chassis system is shorting to ground somewhere. Could be something as simple as a wire with insulation rubbed through.

Are you able to get access to the back of the headlight switch? Odds are the wiring for the circuit starts there, so that would be my first place to start looking for a rubbed spot on insulation. Then I'd follow the harness(es) as it passed through the firewall, bulkheads, etc. looking for a rub point or some type of damage.

You could also have damage caused by mice here. They love to chew on wire insulation, and if they do it in the wrong place it can be quite destructive.

Time to put on the headlamp and begin the search.

twinboat · 09-21-2019, 06:09 AM

As a last ditch effort, I have install a resetable circuit breaker in place of the fuse. Same amperage.

With the breaker resetting, I would walk around feeling the wires, looking for a warmer one. The warmer the wire, the closer I was getting to the short.

It also gave me the opportunity to find a light not lighting or dimmer then the others.

Nalle · 09-21-2019, 06:48 AM

Richard,
Unfortunately, the headlight switch just connects to something called a headlamp module-a black box with two multi pin connectors (12 and 16) for which there is zero information available from either Freightliner or the manufacturer.
And, you are right, there are probably two sources feeding. However, with a short to ground, neither should work?????
Nalle

Nalle · 09-21-2019, 06:54 AM

Twinboat,
The system actually has an automatic resetting breaker. It was burning up. so I had to pull it.
Unfortunately, all wires are hidden inside a big harness, running the length of the coach. I don't want to open up more of the harness than needed. Hoping to locate the area where the seven wires are spliced and then test them all individually.
Nalle

twinboat · 09-21-2019, 06:58 AM

Did you do anything just before the issue came up ?

Screw down something, drill a hole in something, cut into something ?

A poster recently installed solar and sent a screw thru his 240 volt romex cable.

richard5933 · 09-21-2019, 07:02 AM

Quote:

Originally Posted by Nalle

Richard,
Unfortunately, the headlight switch just connects to something called a headlamp module-a black box with two multi pin connectors (12 and 16) for which there is zero information available from either Freightliner or the manufacturer.
And, you are right, there are probably two sources feeding. However, with a short to ground, neither should work?????
Nalle

If the second feed source connects forward of the short it may not be affected, since they probably have diodes in the circuits to prevent one side from back feeding the other.

Even if you can't easily get to the individual wires, it's probably a good idea to inspect as much of the harness as possible looking for wear points, mouse damage, loose connections, signs of water infiltration, etc.

If you have an infrared temp gauge you will be able to detect warmer areas more easily than by hand. They are cheap enough now to be in everyone's tool box.

While you're inspecting, take a look at all the ground connections you can find. Your coach is at the age where ground connections tend to start failing, and it's amazing the amount of trouble that can stem from a loose or corroded ground wire.

Nalle · 09-21-2019, 07:13 AM

Twinboat
No, nothing except scraping off more of the 3M film. Had hitched on the car to go north for a little fishing and when I walked around to check the lights, there were no running lights. Suspected the Trailer plug/cable or toad and since it was daytime driving, I figured I'd check it all at the destination.
Once there, I disconnected the toad and the problem was still there. Then, between fishing excursions, I located all Freightliner/Winnebago connections and tested for shorts there. After that, I was pretty convinced that the problem is in the Freightliner harness somewhere, but is still confused about the marker lights working with the remote clicker.
Nalle
Nalle

Nalle · 09-21-2019, 07:32 AM

Richard,
Interesting that you mentioned diodes. I have been thinking about that and trying to locate.
Luckily both Winnebago and Freightliner has excellent drawing libraries. Unfortunately my subscription to Freightliner had expired so I have reapplied. Now eagerly waiting for new login name and password. Hopefully by Monday.
I do have an infrared temp. gauge so will try with that one too.
My background is electrical engineering and I have done lots of trouble shooting over the years. Problem with RV's are that neither Winnebago nor Freightliner really knows where stuff is located and if/when you find it it is usually totally in accessible. The mess of wires in the footwell is horrendous. Just piles of harnesses lumped together with tywraps.
There are also three multi-pin bulkhead connectors there. I have been trying to open one up to isolate the short. There is not a tool made that will reach the center screw on the connector.
This is not a fun job!
Nalle

ronster · 09-21-2019, 09:39 AM

If the rear lights dont work,I would look for a short there.I've seen bulbs that shorted out internally,also look at socket for toad for internal damage.

jaearhart · 09-21-2019, 10:00 AM

I hade the tail/Break/running lights blowing the fuses. I thought about what was I doing Last before any of this .. I looked at my tow light hitch connection. Because everything was fine till I unhooked the toad connection. I found vibration caused the wires to contact and short inside the 7 pin connector ..

rgvtexan · 09-21-2019, 12:29 PM

Nalle

I just checked my 04 Itasca Horizon, front and rear lights flash with the key fob. Rear marker and tail.

My prints show they are all powered by wire labeled "MM" there is a 7 pin connecter for the rear light. No idea where it is. Wire "MM" also goes to the trailer connections.

I can e-mail you my Freightliner prints. They should be close to yours.

Good Luck
Norm

Nalle · 09-22-2019, 04:27 AM

Thanks to all who offered help and advise.
After much searching yesterday i finally found the problem. The fuse/relay box for the toad connections! The box was very well hidden behind a sheet metal panel in the park cable compartment. A search here on the forum could have helped me locate it faster.
I am now busy ringing out the internal wiring on the Bussmann 31135-0 box. All the eight relays seem fine, but something is screwy inside the box. Can't find a new replacement anywhere - only a used one for $190:- Maybe I can break it open and get inside??
To me it is quite amazing how Freightliner can manage to so carefully hide a box that contains fuses and relays. Would it not be nice to have it accessible??

Nalle

Nalle · 09-27-2019, 04:56 PM

Hi all,

Well my last progress report was overoptimistic. I thought everything was working fine until I took the RV for a spin. After about a mile the marker lights went out again.
Came back to campground and plugged in a new fuse and everything is again working. Now, it is hard to fix it if it ain't broke....
So, since all the marker lights are flashing when I click the door remote I believe that there can not be a short to ground on any of the feeder wires.
Looking at the drawings, that leaves the InPower Head lamp Module 06-44311-000 as a possible culprit. That is the unit that provides power to the relay for the marker lights.
Neither InPower or Freightliner have any drawings or information on the unit, making any kind of testing virtually impossible. Replacements, if you can find them, seem to run in the $200 - $400 range.
I hate to spend that kind of money without verifying that this really is my problem.
Is there anyone one out there that has managed to find any data on this "headlamp module" or has managed to test it??
If that is my problem, I also need to find a contortionist to try to reach the unit behind bundles of wires......

Nalle