No clearance lights

[InTooDeep]

I have an issue that started yesterday. I use 4 different dry vans and 2 skateboards. 2 of the vans have filament bulb clearance and side marker lights. The other 2 have all LED lights. The 2 with bulbs have LED tail and brake lights. Ok here is the problem. The 2 with the bulb clearance and side markers the red clearance at the back and the amber top front along with the rear bottom red marker don't work the tail lights and brake lights work. All lights work on the flatbeds and the other 2 vans (with all LEDs) I have checked power cord for voltage and it shows power there. What the heck is going on any ideas?How can the tail lights brake lights work but not the clearance lights? But all lights work on the LED trailers? Could it be it is getting enough voltage and just not enough current? I used this (see picture) to check thanks

 

[Ontario Outlaw]

Some trailers are wired up to have markers and clearance lights on seperate circuits. Some trucks are wired up to have both circuits run on the same pin, where the trailer maybe is setup to run off two pins

We have at least one trailer that the front two markers are on one circuit yet the rest of the trailer is on a second circuit

What I understand is that the truck needs to be wired to be universal for the trailers

It’s confusing. I don’t get it. But it should all be traceable and fixable

 

[Hillbilly Canuck]

The last time I had one do that it ended up being a shorted exposed wire by the rear bumper fixed with a piece of tape. Couldn't always get it to do it for obvious reasons I now know. Point is something like that could be anywhere and trailer wiring can drive anyone crazy.

 

[Electric Chicken]

I thought you sold your truck.

 

[InTooDeep]

I thought you sold your truck.

Me no I just had it parked while recovering from knee surgery

 

[InTooDeep]

The last time I had one do that it ended up being a shorted exposed wire by the rear bumper fixed with a piece of tape. Couldn't always get it to do it for obvious reasons I now know. Point is something like that could be anywhere and trailer wiring can drive anyone crazy.

I could see that but it is happening to two different trailers. I bought a new electrical cord to try tomorrow

 

[AK7]

How old are the trailers?
I would pull the nose box plug on the trailers and check the wiring.
I'm betting your going to find alot of corrosion or a broke wire.
Start at the front and work to the back.
Or if you have access to all the tail lite wiring,start there and work forward.

This is assuming the 7way out of the truck is working properly.
I'm assuming you spread the prongs in the nose box.

 

[AK7]

Some trailers are wired up to have markers and clearance lights on seperate circuits. Some trucks are wired up to have both circuits run on the same pin, where the trailer maybe is setup to run off two pins

We have at least one trailer that the front two markers are on one circuit yet the rest of the trailer is on a second circuit

What I understand is that the truck needs to be wired to be universal for the trailers

It’s confusing. I don’t get it. But it should all be traceable and fixable

If the trailers are on 2 circuits for the marker lites,you can put a jumper wire in the nose box if you pull the the trailer all the time.
But that will cause problems for a truck that has a separate circuit for the marker lites.

 

[InTooDeep]

How old are the trailers?
The two that are working 2015 the two that aren't 2005

This is assuming the 7way out of the truck is working properly.
I'm assuming you spread the prongs in the nose box.

Yep first thing I tried

Going to hook to different trailer tomorrow to check if the trouble is with my trailers or truck.

 

[AK7]

Yep first thing I tried

Going to hook to different trailer tomorrow to check if the trouble is with my trailers or truck.

Good luck.
Hope it's a easy fix.

 

[r3gulator3]

The leds work because they don’t require the amp load incandescent bulbs require.

You either have a wire rubed thru creating a short to ground or you have a bad ground.

Try clipping a jumper cable to a clean spot on the trailer frame and then to a clean spot on the tractor frame or the batt ground and see if they come on. If not start chasing your rubed thru power wire or bad corroded connection.

If you have a roll up door on this trailer check the wiring behind the balance spring as this is a common breaking point.

 

[InTooDeep]

Good call on the roll up door will check this

 

[InTooDeep]

OK so I bought a new electrical cord that wasn't it. My buddy showed up with his truck and trailer, his truck plugged into my trailers all good. I hooked to his trailer same issue. So now I know it is my truck. So I scrap a place with a screw driver on the trailer frame connect truck to trailer with jumper cables no joy. Might not have gotten the metal on trailer to bare metal will bring a wire wheel tomorrow and try again. At least now I know it is the tractor not the trailer.

 

[Ontario Outlaw]

OK so I bought a new electrical cord that wasn't it. My buddy showed up with his truck and trailer, his truck plugged into my trailers all good. I hooked to his trailer same issue. So now I know it is my truck. So I scrap a place with a screw driver on the trailer frame connect truck to trailer with jumper cables no joy. Might not have gotten the metal on trailer to bare metal will bring a wire wheel tomorrow and try again. At least now I know it is the tractor not the trailer.

Have you inspected where you plug your cord into? Sometimes the wiring in behind that plug, on the tractor, can be funky

 

[InTooDeep]

Not yet was going to start on it today but got a late start. By time I got hooked up with buddy it was well after 1300 and damn if summer didn't hit again it was 99* american. So way to hot to go digging in there sitting out on the asphalt yard. Yeah I know what a wussy. I just will start later so no lights needed till I figure it out. I usually get the green light at the Truckee scale house so I'll just cross my fingers and hope my new 18 inspection stickers on the truck an trailers keep me ok

 

[InTooDeep]

Ok got caught after dark and noticed the LED lights were on but pretty dim. Didn't notice that during daylight. So dug into the fuse box bingo burned fuse. Didn't think to check before because some lights worked guess those were working due to bleed through. Not sure but mystery solved