No Running Lights - Montana Owners Club

jsnip42 · 03-09-2011, 11:37 AM

Just hooked up to get ready for weekend. Checking lights and have no running lights. Turn signals and brake lights work fine. Brake controller seems to be working ok also. Is there a fuse I should be looking for?

dieselguy · 03-09-2011, 12:39 PM

I'd start by checking voltage on your 7 pin connector on your truck. I believe the brown wire is the tail/running lights. It would be the 10 oclock position of the plug on your truck. From there, I'd go to the junction box behind the pinbox on the fiver. With the pigtail hooked to your truck, again check the brown wire inside the junction box for voltage.

jsnip42 · 03-09-2011, 01:14 PM

I tried plugging the trailer in both the factory plug in the bumper and the plug in the truck bed installed by dealer. Both work everything but running lights. So I guess it must be in the Montana. I don't have a meter so just hoping for a fuse somewhere.

dieselguy · 03-09-2011, 01:34 PM

I was assuming you had tail lights on your truck without being hooked to your fiver. The dealer installed bed plug is simply an extension of the factory wiring. I don't believe there is any "fuse" on your fiver for running lights as that would be taken care of by your truck fuse. You should try and borrow a meter and see if you have 12v coming from the brown wire inside the JBox behind your pinbox. Additionaly ... there will be a bundle of white wires secured by a large wirenut inside the JBox. Make sure none of these wires can be pulled out from the group as one of these white wires is the ground for your running lights. Sometimes the actual color for the hot wire on the running lights is white with a green stripe. If you don't have tail lights on your truck and after replacing the fuse on the truck, it blows the fuse again after hooking up your fiver pigtail ... you probably have a short somewhere on your fiver.

On edit: when you say everything works but ... do you have tail lights on the fiver, but just no running lights?

jsnip42 · 03-09-2011, 02:14 PM

The truck works fine. When I plug in the Monty and run a check of the lights the turn signals and brake lights work. The brake controller comes on and appears to work. Only thing that doesn't is the running lights. (lights on top of cap, side marker lights, and tail lights) does not work. Since the truck all work I guess it has to be in the Monty.

CORattler · 03-09-2011, 03:23 PM

... might try running a continuity check from the umbilical connector to one of the running lights.

Quote:

quote:Originally posted by jsnip42

The truck works fine. When I plug in the Monty and run a check of the lights the turn signals and brake lights work. The brake controller comes on and appears to work. Only thing that doesn't is the running lights. (lights on top of cap, side marker lights, and tail lights) does not work. Since the truck all work I guess it has to be in the Monty.

Slufoot733 · 03-09-2011, 03:34 PM

Get you trucks owners manual in your hand and study the fuse box diagram. There are two fuse boxes, one under the dash and the other under the hood. All the fuses for the trailer are under the hood. Open the fuse box and find the fuse for your trailer running lights. If you don't have a meter or continuity tester then pull the fuse and check it visually. Chances are that the fuse has blown. I think it's a 15 or 20 amp fuse. Replace the fuse with the proper match fuse. Hopefully this will remedy your problem. It's not unheard of for a fuse to simply pop for seemingly no good reason. I had this occur on my 2008 F-350. I carry several replacement fuses with me all the time. I've replaced this particular fuse twice and have never been able to fine any short circuit or any other problem. Good luck and let us know what you find.

KT

racerjoe · 03-09-2011, 03:50 PM

It dosen't take much to slide open the 7 pin connector on the monty. It could be nothing more than a loose wire inside the connector. In 5 minutes you will know.

GregN · 03-10-2011, 02:32 AM

Have the lights worked before. Another thing to check is that the contacts are clean. Cleaning the pigtail and truck plug. Some fine sandpaper on the contacts, blow out the dust and they work. Could be it's just the contact is dirty.

jsnip42 · 03-10-2011, 03:06 AM

They worked fine last trip about 2 weeks ago. When I get home from work (YUK) I am going to try and check fuses under the hood as suggested by Slufoot. The plug on the truck was replaced last week and I was thinking maybe a fuse got blown on the camper. Maybe I can find it on the truck. Thanks for all the suggestions.

**Carl n Susan** · 03-10-2011, 06:21 AM

Quote:

quote:Originally posted by jsnip42

...The plug on the truck was replaced last week and I was thinking maybe a fuse got blown on the camper...

No, a fuse in the truck got blown. My Fords have all been susceptible to blowing the various trailer related fuses under the hood when plugging in the RV with those circuits energized. The most common is the tail light circuit as it stays on all the time when the lights are on. The brake lights are only energized when the peddle is pushed so it rarely fails.

Check the Trailer Light fuse under the hood. If it stops raining here I will go figure out which one it is.

jsnip42 · 03-10-2011, 11:30 AM

Found problem. Fuse number 38 inside dash panel was blown. Everybody really came through for me. Thanks guys!!

Parts Ed · 03-10-2011, 11:50 AM

At our dealership we advise customers that once they are hooked up to their RV, to shut the truck off and then plug the RV in to the connection. Sometimes plugging the trailer in the truck will blow a fuse.
My 2c worth.....

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