Trailer running lights not working

[LovenLifeGuy]

Im leaving for milacs in a couple hours and when I hooked up my boat I noticed my running lights are not working. All the other lights are working. I noticed this last time I pulled it but a buddy of mine pulled it for me the last time out and it worked fine on his truck, so I thought I just didnt have it hooked up tight. My first guess is that its a fuse. Anybody know which one? Or have a better idea what it might be?

Thanks, LovenLifeGuy

[Shack]

What year make and model. It might be a fuse!

[Shack]

I would check fuse box under hood if it is a newer model!

Most times fuse panel under hood is located on drivers side of eng. bay twords fire wall. Most times it is a black box with a flip top cover saying fuses on top of box.

Take a flash light and look for blown fuse! If you have manual for truck, try to locate fuse in book! My way would be to ground a test light and turn running lights on and prob back side alum. slits in fuses untill I found one were after probbing both sides of fuse, test light does not light up.

Good luck!

P.S.

If you find a blown fuse, most likely it was a ground issue with trailer. If fuse blows again, wiggle lights aournd on trailer and look for corrosition.

Could be a ground isse all to gether!

[LovenLifeGuy]

Thanks, its a 04 chev silverado. I checked and I could not find a bad fuse. I think you may be right with the ground issue.

[Kyle Sandberg]

Had the same problem with my old boat. IF your other lights are working, your ground is probalby OK. I think you said you checked, but did you look in the right box. The fuses for trailor ligths will be under the hood, usually behinde the battery somewhere. They have the small fuses that are hard to tell if you have one blown.

[Shack]

I have a buddy who has a 2007 Chevy 3/4 ton and two trailers with this same concern! He had rewired two trailers to find concern, but it did not fix problem. We were fishing the Croix and when we were done, loaded his boat up and by then it was dark. He was worried about the drive home with no trailer lights. It was late and I muttled around with the though of getting into a big diag thing at launch! So, I had him pop hood, took a flash light and went down rows of mini fuses and found a blow fuse. Went under dash and showed him the other fuse panel with the spare fuses and fuse puller in it(its a wounder how many people do not even know they have a fuse panel under the hood of their Veh.).

Replaced fuse and I tell ya, I was king the whole drive home. This was one of those things that plegged him for some time and now was fixed. Like I said, he rewired two trailers and even bought two new seal led light housings that were not cheap. I fixed it with a 20 cent mini fuse.

Good luck!

P.S.

Good luck at Mille Lacs!

[LwnmwnMan2]

FYI, I know it's not a concern with this truck, but.....

I've got a 2006 Dodge Ram 2500. Something chewed through the wiring harness on my enclosed mowing trailer and shorted it out.

I searched hi and low for the fuses in this truck, now there's only one block under the hood, no more fuses inside the truck.

Also, there's no fuse to blow. What happens is it trips a module called "TPMI" or something like that, and you have to go back to the dealer to have it reset.

After 5 trips, you have to have the module replaced.

I was somewhat upset when I found this out, pretty stupid if you ask me. So if it's 11 pm on a Saturday night, I back the boat in the water and for whatever reason short out the lights, there's no instant fix now.

It's even more rediculous, because the dealer says "well, must me something wrong with the lighting on your trailer". I'm thinking, ...... "REALLY???"

[Shack]

LM2,

You could be right! I did not see the fuse thing with Rams that much, only Fords and it was on a Friday after noon always heading up north. Fords were a quick fix!

I do think I remember a Dodge truck with your concern. I think it has some internal Body Control Module switch or breaker, computer controlled. Further, I do remember having to replace the BCM in one case. I think they are hardier than a mini blade fuse, but if your trailer has a major ground or wiring issue with it, the computer will go into a limp mode and shut that area down. Thus the only way (at this time with out spending a couple grand on a tester) is go to dealer and have it reprogrammed. But! In some cases, they had to replace the module all together! That isn’t cheap, $400-$500, plus install and any diag... Basically the computer resets until is goes bonkers trying to figure out what is up and shuts down. In some cases (like yours) the computer will internally short out or burn out because of an issue down the line!

[Hookmaster]

I had the same thing this spring. It was one of the fuses under the hood. Look in the owners manual for which one. There are separate ones for almost every light. In my troubleshooting I did find some corrosion in the round trailer connector though, but this wasn't the fix, the fuse was.

[Shack]

Correct Hookmaster, not the fix, but the cause (possibley).

Did you fix ground and if so, has fuse blown since then.

The reason I ask, is because I feel it is most times the main ground point on trailer that causes fuse to blow. Just asking?

[LovenLifeGuy]

I did check the fuse box under the hood also before I left and all were good. Im not sure but I hooked up to my brother in laws truck today and it worked on his truck also. I guess I will check the fuse box again, I could have missed it I guess.

Thanks

Oh, the fishing was ok. 13 fish from 9pm-midnight

[Kyle Sandberg]

Sounds like exactly what happened to our boat. Didn't work as long as we had it. Sold it, the guy backed his truck up, connected the lights and bingo, they worked. At least now you know there is nothing wrong with the wiring in the trailor. If you can't find it, bring your truck to a repair shop or such and have them lood it over.

[LwnmwnMan2]

Head out to Wal-Mart, Northern, Menards, local trailer dealer, wherever, and they should have a plug-in that will also have lights on it.

Put that in your receptacle and turn on the lights. There should be lights that will light up for each light that you turn on. Either that or get a tester and try each of the 'prongs' in the truck. This way you can eliminate the truck or the trailer.

[Shack]

That or take a test light and gound it and prob each term in your connector on truck. With head lights on, running light term should glow test light solid. With blinker on left or right, the test light bulb will blink. Brake light term when probed, will glow solid as long as brake light pedle is pressed.

[Shack]

Hey, Loveinlife!

Were abouts do you live or work? If in Elk River area, you could stop by and I will take a look at. I spent the morning tracing down a L.E.D. short in our new hauling rig.

I tried to find fuse diiagram on line, but no luck!

Never rule out trailer! Every thing may work great at one point, but rolling down the road and hitting bumps causes more issues, that correct them selves right away, but blow fuses at that moment! Hook up to another truck and light work fine, but on the last truck, nothing works!

Unless like M2 said, a mouse! Possibley a worn wire on truck!

Very, very, very rare!

[Jeremy airjer W]

underhood fuse block on drivers side of the vehicle. There will likely be a blown fuse. Just had a simular issue with my dads chevy except one of the turn signals wouldn't work. He looked at me like I was crazy when I told him there on seperate fuses! L. and R. turn signals are on seperate fuses so it is possible that it can blink to left but not to right.

Its deffinitely not a ground issue. If it where it would do funky things like the running lights would go out with the brakes applied or the brake lights will only work with the running lights on.

If its funky its usually a ground issue. If its straight forward (everything works except this) its usually a power issue.

[Shack]

Airjer,

You are correct! People sure give you a funny look when you say fuse and tell them how many fuses controll their trailer lighting system on late model Veh...

The one thing though I always think about when I am putting a new fuse in PD box, "What caused it to blow". There is about a one in a million chance the fuse was faulty and had a weak elem., people always ask about that being the case.

P.S.

Nice panfish Airjer!

[LovenLifeGuy]

shackbash, thanks for the offer to give a guy a hand but I found the bad fuse this morning and it appears to be solved. Not sure how I missed it the first time. Thanks everyone for the help

[Hookmaster]

The ground wasn't the issue since everything else was fine. It has worked all summer. You are right the corrosion most likely caused the fuse to blow.