Why do trailer lights keep blowing trucks fuse?

There is a 20 amp fuse in the passenger kick panel that controls the trailer’s running lights (brake lights and turns are another circuit) that keeps blowing. Interestingly we also have an 2001 Expedition with factory tow package that doesn’t have this problem. Truck is like new (24k miles) and just developed this issue. Any ideas?

How can I troubleshoot a wiring problem on my trailer?

Perhaps the most helpful thing you can do to start troubleshooting is to determine whether the problem is on the tow vehicle or on the trailer. When you use your trailer to test, you have no way to know for certain whether the problem stems from an issue with the wiring harness because the trailer’s wiring system is still part of the equation.

Why are the lights on my tow truck not working?

Check the fuse on the powered converter to ensure it is still functional. Take a look at the tow vehicle lighting fuses. Examine the wiring on the trailer side and vehicle side for in-line fuses. If the blown fuses continue, it might be the result of the circuit being overloaded. One solution is to replace the trailer lights with LEDs.

What is the problem with my intermittent trailer?

About a month or so ago the problem started to get really bad and it was happening far more often. I was able to determine it was definitely a trailer wiring issue and not a problem in the truck by putting a fuse across pin 3 and 4 on the 7 way plug. Usually this lights up the marker lights but this time it blew the fuse instantly.

Why does my Fuse blow every time I connect my trailer?

It sounds like there is a short somewhere along the wiring of your vehicle or trailer that is causing a fuse to blow every time you connect. The first thing I recommend doing is disconnecting the trailer and using a circuit tester like # PTW2993 to test the vehicle side connector.

Why are my brake lights not connected to my trailer?

(Hard Wire Only) Vehicle has separate turn signal and brake lights, brake wire is not connected. Insufficient ground or short to ground on trailer or vehicle side. None of the trailer lights work for any functions. (Powered Converter Only) 12V power wire is not connected to vehicle battery.

When to troubleshoot a tow vehicle wiring problem?

A lighting problem can originate at any point along the wiring on either the tow vehicle or the trailer, so it is important to determine not only what is causing the problem, but where it is located. The question the troubleshooter will find themselves asking is “There are so many things to check. Where do I start?”

Is it OK to replace a blown fuse?

Never replace a fuse with a higher amperage rating becouse your device can draw more current than its supposed to and whole thing can blow in your face. NEVER OPEN DEVICE THAT IS STILL CONNECTED TO MAIN!

What should I do if my tow light keeps blowing?

Curt makes a “T” harness that can plug into the harness behind the bumper. People use that for wiring in the under tailgate light bars, or to use a 7 pin plug in the box to use with 5th wheel trailers. With this type of testing you will be able to see if the problem is at the back of the truck, or if have to start trouble shooing further forward.

Where do I plug in trailer tow lights?

From there you could continue on by pulling the wiring harness apart behind the bumper and check for shorts there. Curt makes a “T” harness that can plug into the harness behind the bumper. People use that for wiring in the under tailgate light bars, or to use a 7 pin plug in the box to use with 5th wheel trailers.

What causes trailer tow lights to keep blowing?

When you drive, and hit a bump or a curve, the wiring in the trailer moves a bit, the bare part shorts to the frame, blowing the fuse. When stopped, if the bare spot isn’t touching the frame, the fuse will hold. Mice are the worst… Click to expand… Yes, I drove around with the trailer connected to the Yukon.

Why does the fuse keep blowing on my Dodge Ram?

I have seen mice get into the wiring, eating the insulation. When you drive, and hit a bump or a curve, the wiring in the trailer moves a bit, the bare part shorts to the frame, blowing the fuse. When stopped, if the bare spot isn’t touching the frame, the fuse will hold.

What to do if your running light fuse keeps blowing?

Replace the fuse and then use a circuit tester such as # PTW2992 to test the vehicle side trailer connector while someone sits in the vehicle and turns on the running lights. If it shows power and the fuse does not blow then the issue is on the trailer. If it does blow the fuse then the issue is on the vehicle.

Why is my tow package running light not working?

If it is the tow package running light fuse that is blowing then there is most likely a short in the trailer wiring or in the trailer or vehicle side connector. What you will want to do first is make sure both the vehicle side and trailer side connectors are clean and free of corrosion inside and out.

What to do if your trailer tow light keeps blowing?

By using an replacement 7 pin plug with nothing attached to it might determine if there is a short right in the truck connector itself. From there you could continue on by pulling the wiring harness apart behind the bumper and check for shorts there. Curt makes a “T” harness that can plug into the harness behind the bumper.

Why does my running light keep blowing out?

You have a short circuit somewhere that is causing the fuse to blow. To determine where the short is start by disconnecting the trailer from the tow vehicle. Replace the fuse and then use a circuit tester such as # PTW2992 to test the vehicle side trailer connector while someone sits in the vehicle and turns on the running lights.

Why do trailer lights keep blowing in Yukon?

It’s not the trailer because I then hooked it up to my Yukon, and the running lights on the trailer work fine, and STAY ON with no fuses blowing in the Yukon. Any thoughts on this? Thanks!! Did you drive the Yukon with the trailer connected?

Why does my F30 keep blowing a fuse?

Most likely cause of blown F30 fuses to me seems to be a bad “Trailer tow relay parking lamp” in the battery junction box. I’ll yank that an see if I keep popping fuses. Any smart electrician guys have any other bright ideas given this wiring diagram? Problem solved once and for all.

Why does the fuse keep blowing on my trailer?

If it shows power and the fuse does not blow then the issue is on the trailer. If it does blow the fuse then the issue is on the vehicle. Likely causes of a short on a vehicle include a dirty or corroded trailer connector or damaged wiring.

Why does the fuse keep blowing on my car?

If it does blow the fuse then the issue is on the vehicle. Likely causes of a short on a vehicle include a dirty or corroded trailer connector or damaged wiring. Make sure the trailer connector is clean (go ahead and do the same for the trailer side connector while you’re at it).

What are the fuses on a Ford F-150?

Ford F-150 fuse box diagram No. – Type Description 1 fuse 10A mini Run/Accessory – Wipers, Instrument clust 2 fuse 20A mini Stop/Turn lamps, Brake on/off switch, Ha 3 fuse 7.5A mini Power mirrors, Memory seats and pedals, 4 fuse 10A mini DVD battery power, Power fold mirror