OK let me start off by saying I'm no electrician. I can boggle through your basic circuitry and I thought that's all this was. The truck is an 01 F150, it came from the factory with a 4 pin plug, which has long since corroded. I replaced it with a new "PLUG IN SIMPLE" wiring kit from Hopkins(used to be 'Hoppy') that requires no splicing, just plug it in. It is still 4 pin flat. I just bought a brand new trailer, and the wiring wasn't working when I brought the trailer home. The trailer has a 7-pin round plug. I made an adaptor to go from the 7 down to the 4 on the truck, using all new plug ins. I traced the original problem to my home-made adaptor, and that has been fixed. Everything WAS working correct, parking lights, right turn, left turn(that's all the 4 pin allows for). However, NOW it is acting up again. the right turn and left turn work, but everytime I turn on the parking lights the fuse blows under the hood. I checked and rechecked the wiring using a battery, all the lights working through the 7 pin and the 4 flat adaptor. This leads me to believe it's in the truck. Any idears?

 

I would check the quick fix connection for wires touching. Also do you checks from th wiring kit where it plugs to the truck. Or use an ohm meter to check for resistance from the quick connect back (unplug trailer) if you have a short then try to narrow it down.

 

Does your new trailer have electric brakes?

Steve

 

Hooking a battery to your trailers lights and seeing them work does not mean that the trailer is not the problem. The battery hooked straight to the lights will have no fuse to blow. When hooked to the truck the fuse is sensitive enough that if there is the slightest short the fuse will blow.

 

RIP IT OUT AND DO IT RIGHT!

You don't have at least two things you need for the trailer - a charge wire for the RV battery (part of the seven pin connection) and wiring for a trailer brake.

NOT TO MENTION A BRAKE CONTROLLER.

Without a properly wired (WORKING!) brake controller activating your trailers brakes, it (the trailer) could easily ram you into a bad situation. And that could be very destructive...

This all sounds like very bad juju...

The dealer you bought the trailer from should have advised you of all of this.

A four pin CANNOT HANDLE YOUR TRAILER! And NO adapter made can fix the problem. Four pin connectors only give you turn, brake, and running lights - THAT'S ALL, man!

Absolutely not. You need to upgrade the wiring in the tow machine.

If the plugs in the four-way were corroded in the first place, no adapter stands a good chance anyway. But in addition to it you need the other connections a seven way provides.

Look in this forum about that and you will see what I and others have posted about it.

 

Will borrow my buddies ohm meter this afternoon if the weather clears.

Yes the trailer does, but my truck is not wired for it nor do I intend to wire it for brakes. The trailer has way too big a capacity to be hauling with this 1/2 truck.

Ok but it would show if the trailer was not properly ground or if there was a short in any of the light circuits, which is what I was checking for. No unneccessary lights light up when i check it this way and none of them are dim light a bad ground. I checked by sticking wires into the plug in's to make sure the plug ins work.

OK I 100% understand where you're coming from and I won't call you wrong, but I understand the capabilities of my 1/2 ton pickup and there is NO reason I should not haul this empty trailer around with no brakes. It weighs 2500 LBS and that is nothing compared to what I have hauled on this truck, in my opinion safely. I have no intentions of loading down this trailer (12,000lbs GVW) and hauling with the 1/2, that is pretty dumb. I have an F350 to haul with, but it doesn't belong to me, and I want to be able to move my trailer around with out driving down and borrowing my dad's truck everytime I want to. A four pin will handle the trailer once I chase down the short. Now that you have the whole she-bang can you try and answer the question without assuming I don't know what is going on and how to safely haul a load on a heavy trailer. I been hauling since I've driving at 16, and I'm much more capable of doing it safely than most twice my age and driving experience.

 

thanks for all input, fingered it out, had loose wire on plug in.

 

Scottie -

Glad to hear you got 'er fixed. BTW, you gave no indication in Post #1 that "I want to be able to move my trailer around with out driving down and borrowing my dad's truck everytime I want to". If that only includes moving it around a lot and not on the street, then fine. If it's gonna be on the street behind your 150, then Wolfie and I were concerned about your trailer not having functional brakes. Sorry you felt we were questioning your extremely vast towing experience and needed to cop an attitude about it.

Steve

 

The weight isn't the issue, nor the loading of the truck - the issue is that you only have F-150 brakes to stop that thing with...

Trailers have brakes for a reason. That reason is to take the braking load off of the towing machine, because six or eight tires with brakes are better than just four.

With an F-150 and no trailer brakes, you can expect the mass of that trailer to roll you right out into an intersection, especially if the road is wet.

NOW:
I've expressed it, and hope you don't take offence as it was not meant unkindly. Even unladen you have half a ton behind you. Keep it in mind. You can give your truck advantages - people pull loaded RV's all the time with half tons, but not without the right gear.

On your own head be it.

 

Scottie glad you figured it out. I think you all so found when you post a question on the internet you open yourself to all kinds of stuff.

 

What can I say? I always think of safety first.

I hate to think he's putting himself in danger.

 

Does the fuse blow when the trailer is not connected?

If not, then the problem is in the trailer.

Unless the fuse is the wrong size (too small).

There are only 2 things in the trailer that are part of the system. Wires and lights.

Every couple of years I pull all the marker light lenses to clean them and replace the bulbs. Take a look at them and see if one is damaged or any wires look out of place.

Next would be the wire chafing somewhere. Maybe not a complete short, but enough to blow your fuse. If you take all the bulbs out and measure resistance to gound, it should be infinite (or as high as your meter will measure).

If resistance is low, leave the meter hooked up and hand over hand the wiring as much as you can and the ground should clear when moved away from the chassis.

Good luck.

Greg

Edit: Didn't see he got it figured out a few days ago. At least my post count will benefit.

 

If you pull any marker lenses, it pays to put a bead of clear silicone over the top, and down both sides. DON'T seal the bottom. Residual water will have a way to run out if you leave it unsealed.

 

Scottie,
Glad you got it fixed.
Greywolf is exactlly right you may not need the brakes to stop your trailer however, It is the law in MOST states that a trailer over 2000 lbs or 40% of the vehicle weight MUST have brakes. So if its raining and you are justr running to the rv store with it and you hdroplane and hit someone you may get a legligent ticket for not having proper working brakes. But I will tell you that I have done the same thing. Just want you to know that it is the law in most states.