Suddenly...No tail lights, running lights or license plate light.

[kevin donald]

I plugged our '2000 E350 Chinook Baja into a 4 pin trailer connector for our small utility trailer. All was good until... I lost my tail lights, running lights and license plate light on the Chinook. I disconnected the trailer. The turn indicators, back-up and break lights still work on the Chinook,but not the tail lights running lights or license plate light. Turn indicators, and back up lights are working fine.
I combed through my owners manual looking for the appropriate fuse or relay but tail lights are not mentioned as far as I can see.

Any advice? Many thanks!
Kevin

[chin_k]

Did you check the Ford manual for the fuses? They are under the dash near the driver's left knee.

[Barrera]

Check out this post: viewtopic.php?f=8&t=548&hilit=Fuse. It deals with the same issue and was very helpful for me.

[kevin donald]

Did you check the Ford manual for the fuses? They are under the dash near the driver's left knee.

Yes I checked all the fuses under the dash as well as the fuses and relays under the hood. Spoke to a Ford mechanic as well who had no experience with Chinooks but lot of time with E350 Fords. Turns out that Trailways/Chinook used a rather "novel" way to run power to the tail lights and coach running lights. Have a look at this link that Barrera was kind enough to share. Talk about a "rabbit hole" viewtopic.php?f=8&t=548&hilit=Fuse. I will begin looking for the mysterious 7.5 amp fuse tomorrow. Cheers!

[kevin donald]

Check out this post: viewtopic.php?f=8&t=548&hilit=Fuse. It deals with the same issue and was very helpful for me.

Thanks so much for sharing this link. Wow! Talk about a "rabbit hole" I read all of it and will pursue my search for the elusive 7.5 amp fuse that lives in the secondary fuse box under the steering column with pirated juice running through 40' of wire just to run the tail lights and coach running lights. I have to say this is the first thing about my Trailways/Chinook coach that appears to be poorly conceived and executed. I will let you know if I get this figured out. I will definitely replace my trailer lights with LEDs so as to not futher overload an already overloaded circuit. Thanks again for the link. Cheers!

[chin_k]

What year is your rig? For mine, the 7.5 A fuse is right in front of the Ford fuse box by the knee. There is a diagram of it in the long thread that Barrera linked.

I wonder if a better way for Trail Wagons to do was to "short cut" the loop from the trailer wiring to the fuse box to the marker light by having a fuse box in the rear. The new rear fuse box should have a much shorter wire to where the TW folks tap into the power, and shorter distance to the lights. Did not know all the details about the location of the tap (I kind of remember that it is from one of the "shnozzle" adapters that were hanging on the chassis frame.... maybe Blue can confirm that.), or where does the wiring goes after leaving the fuse box to the light.

[Blue~Go]

Most of the info is probably in the other thread, but yep, essentially Ford provided a pair of connectors ("schnozzles") back at the driver's side frame rail where it ends by the spare tire. These were for trailer lights. The brown one is the basics, and the black one is the "extras" (beyond the basic four).

Chinook brilliantly decided to use those for the taillights and marker lights. And hey, while we're at it, let's put the fuse up in the cab so we can run the wire back (Ford), forward (Chinook), and back again (Chinook). And let's make it skinny. Now when someone hooks up a trailer with lots of incandescent lights... poof! goes the fuse.

This happened to me when I hooked up a Haulmark cargo trailer with like TWENTY EIGHT incandescent lights on it (my boat trailer only has about about nine, most of which are LED so it had never been a problem). I was halfway through a trip so I disconnected a few of the trailer running lights just to get away from a crowded truck stop area (a friend was following me anyway), and then ordered a set of LED lights for that trailer (that solved the too-much-draw problem).

Chin_k, I thought about that too - why go up and back and up and back, etc. But, I'm not sure where the marker lights wires come in. Seems like the front ones might be up front anyway, so now you are going up and back regardless. (Been a while since I've really thought about it though.) If I were going to run any more trailers with gobs of incandescent bulbs, I'd probably make the up and back (Chinook's two legs) be heavier wire. It's easily replaceable (run is easy to get to). As it is all my trailers have LED lights so I have not blown the fuse again since that time in 2016.

Yeah, kind of a silly shortcut on their part. Just run your own darned wires for Pete's sake and leave the trailer schnozzles for... trailers!

[kevin donald]

Now that I known where to look, I was able to easily locate the fuse box with the 7.5 amp fuse that controls the tail lights, exterior coach running lights (marker lights) and license plate light. Yes, the fuse was blown. I replaced it and everything works fine now. I will now replace the lights on the the trailer with LEDs. By the way, in my earlier post I mentioned that I had looked at my "owner's manual". I was referring to my '2000 Ford E350 manual, not my Chinook manual. Had I used my Chinook manual I might have seen the auxiliary fuse box with the marker lights fuse. My bad.
Thanks for the advice, it is much appreciated.
Cheers!
Kevin

[Barrera]

That's great news! I'm glad it was an easy fix.

[BoomBoom]

Out of curiosity, does this same wire control the backup lights? I kind find nothing wrong with my neutral safety switch but the reverse lights won’t go on.