Help and advice needed! Daylight/nightlights not working when plugged in truck.

**Speak.life** · 11-03-2019, 02:42 AM

Hi all, new- bee here, in need of an electrical advice from my fellow passionate GD owners. We have a 2019 3740 BHS S class and are full timers from almost a year. During our last move to another campground our rig day/nightlights stopped working. Our break lights and our turn signals work - but nothing else! Really scared of driving after sun down . Please, advise if someone has experienced similar symptoms? Or if you think that the issue is in the pigtail connection / or plug of our dually? Thank you all in advance!!!!!

**FT4NOW** · 11-03-2019, 06:38 AM

I would get a meter and check your truck first. Turn on the truck lights and test the different connection points. If your truck connection is in the truck bed, also try plugging it in to the bumper connection to see if anything changes. If the truck checks out good then your problem is obviously with the trailer. If the truck is bad, I would look at fuses for your truck. If the trailer is the culprit, I would start by looking up inside the pin box, there is a junction box where your trailer plug wires come in, it's possible something is loose inside there. If you set your meter to check continuity, you can check each point of the trailer plug by putting one end of the meter on the various trailer plug connections and the other end on the wires inside that junction box I mentioned. I dont recall if there are fuses on the trailer for running lights.

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Attachment 23390

**Buckskin** · 11-03-2019, 06:55 AM

Google to get 7 pin hitch connector diagram for truck. Take voltage meter and check to make sure you have voltage from your truck; if not check your fuses. Something could have short circuited and blew a fuse. If you have voltage check your campers fused next; more than likely it will be blown fuse.

**Speak.life** · 11-03-2019, 07:18 AM

Originally Posted by FT4NOW

I would get a meter and check your truck first. Turn on the truck lights and test the different connection points. If your truck connection is in the truck bed, also try plugging it in to the bumper connection to see if anything changes. If the truck checks out good then your problem is obviously with the trailer. If the truck is bad, I would look at fuses for your truck. If the trailer is the culprit, I would start by looking up inside the pin box, there is a junction box where your trailer plug wires come in, it's possible something is loose inside there. If you set your meter to check continuity, you can check each point of the trailer plug by putting one end of the meter on the various trailer plug connections and the other end on the wires inside that junction box I mentioned. I dont recall if there are fuses on the trailer for running lights.

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Attachment 23390

Thank you so much for the invaluable advice!!! Much appreciated!

**Speak.life** · 11-03-2019, 07:19 AM

Thank you very much!

**cfowler55** · 11-03-2019, 08:10 AM

Don’t know if you have this repaired yet. Most modern trucks have dedicated trailer lamp fuses so if you have an issue it doesn’t take out the tow vehicle lights as well. They are usually identified on the fuse box cover and in the owner’s manual.
Charlie

**boyscout** · 11-06-2019, 09:16 AM

@FT4NOW's post includes a link that's giving a "bad attachment" message. I'll bet he was linking to something like the following, a pin-out diagram that may be for the connectors you need to check.

I don't think anyone has made the point yet that if your testing shows that your truck is not sending electricity to the lights, a fuse in the truck may be the issue.