'02 F350.....I have no brake lights on trailer, nor blinkers, but running lights are fine. All lights on truck work. My brake controller is not working (no trailer brakes) and the signal strength light is very dimly lit green (sometimes).

I checked all fuses in fuse panel...all wires are coonected and look ok on trailer plug. Any ideas on where to look next.

I'm kind of clueless on this stuff thx

 

Turn signals have their own fuse for the trailer so check the fuses with a meter or test light.

Is the white wire on your trailer hooked up to anything? Many times wiring issues are just a bad ground connection between the truck and trailer.

 

As far as your trailer brake signal strength light what kind of controller is it?

Does that green light on your brake controller stay on all the time when a trailer is connected? (To show your brakes are working)

I would venture to say you have a ground issue or loose connection someplace for the trailer brake light being dimly lit sometimes.

Have you checked your fuses in your fuse box under the hood as well? Forgive me but I found this out the hard way. There is a seperate fuse box under the hood near the master cylinder that contains all the fuses for the trailer circuits as well.

Is this a trailer you normally tow?

And was everything working properly last time you pulled it?

After checking fuses in the fuse box under the hood I would take a test light and a friend to check each circuit at the trailer plug and see that you have power there.

I know on the farm once in a while we end up with a rodent that chewed through or made a mess of the wiring.

You didnt happen to paint your ball or anything since the last time or installed a new stinger?

Hopefully someone else will be along shortly with more info.

 

Do the 2002 trucks have a fusebox under the hood? I had a similar problem with my 2001, but it was tail lights instead of brake/turn lights. Turns out it was a bad fuse in the under hood fuse panel.

 

No. They moved all the fuses under the steering wheel in 02. The under hood box was MUCH easier to change blown trailer fuses in. No having to crouch down and try and find which fuse is the trailer one.

 

I was just looking at the 2002 owner manual and fuse #6 20A Maxi is designated for Tailer tow turn/stop relay. Either the fuse is bad or the relay it powers is bad????

After looking a couple of times I didn't find a fuse for trailer tow turn/stop lamps??? Can someone look at their 2002 nanual?

Tailer tow electric brakes is fuse #101 30A Maxi. That dim light may be a bad ground as Chris mentioned.

Wiring diagram showing Trailer tow turn/stop lamp relays. Wiring diagram and owner manual fuse designations differ.

Check out that fuse #6, I doubt you have 2 bad relays, but you never know.

 

I will double check fuses, all of my fuse boxes are under dash by driver. Yes, I tow the trailer daily and it happened a few days ago.

If it was a bad ground wouldn't it cause none of the lights to work? Thanks for the input so far.

My controller is a Tekonsha Voyager

 

OK, i found a blown fuse...#115 a 20 amp tow package (battery charger) fuse, replaced it, and it didn't do jack didley.

That seems coincidental doesn't it. Something is crawling around the wood pile (as my daddy used to say).

 

One place I had a problem is where the harness plugs into the back of the 7 prong plug,I had lots of corrosion

 

Ive got the exact same problem with my 02.
I know its the truck because I plugged the trailer into my 96 and everything works fine.
I have tailights but no brake or signal lights.
Theres no fuses under the hood on a 02.

 

Any other ideas on this guys?

 

Go from the plug at the back and follow your wires up to a big plug that joins your 7pin plug to the truck and check that connection as well ! I had problems there with mine... Although that plug on mine is broken and I have to tape it all together good and tight... You may have a loose or corroded connection ??

 

Did your #115 blow again by any chance? Have you tested the leads at the trailer connector? That would be where I'd go next. You'll want to test for high resistance (open short) on your ground lug. On your trailer, do you have to use an adapter to make it work with your truck? Seen bad things there sometimes.

 

Fuse #101 is you electric Trailer Brake fuse (30amp maxi fuse), #6 is trailer turn/stop lights (20amp mini fuse) and #38 is your trailer lights (20amp mini fuse.)

 

No, I do not have to use an adaptor. As for the connection from my 7pin to wiring harness I am going to check that today. Does one of my 300# relays work the trailer brakes? I'm thinking one of relays went bad and caused my 20amp maxi to blow....(see above post) is this a possibility?


Thx for all the help