Without looking, the only thing I can think of off the top of my head is someone simply wired it up wrong.

 

agreed you need to check the wiring something got crossed

 

My HiBeams and LowBeams were backwards shining on the road.... Indicator on dash was right but lights were wrong... The bulbs were installed wrong.... The bulbs can be put in 3 possible ways.. Rotated them one notch, (about 30 degrees) and now hi is hi and low is low.... You would think those would go in only one way.... WRONG !!!


Dan

 

Thats true. Anything is possible. Nothing surprises me.

2005 F250 Powerstroke 6.0 DieseL

 

The first thing i notice is that the taillight assemblies are mounted backwards (the left is on the right and the right on the left).
Second, these look like three light assemblies and you only had two light sockets, so the backup lamps are not connected.
I am just basing this on the rear wiring on my '06.

 

Thanks for your comments Crankcase. But as i mentioned in my earlier posts, the bes that I have on my 05 f250 is bed from a 2008 truck, and the taillights on newer models look like that. Actually it is how they look like on the video. Also there are only 2 holes on each one of them. Top portion hole is for backup, and the bottom has another hole for running and turn signal bulb.[dual bulb]
I think the problem is in the wire harness, the plugs are identical but, wiring is different. I am going to check it when i get a chance.

2005 F250 Powerstroke 6.0 DieseL

 

Your tail light assembly's are not backwards some think that because earlier years had the back up lights on the bottom 2008 they are on the top. The wiring harness for the '08 is a little different than earlier years so someone may have miss wired your truck, the bulb wiring has to be lengthened so maybe they got crossed when that was done, you also could very easily have a bad ground, that can cause all kinds of weird reactions with the lights. I would pull the lights out and check each wire at the socket with the bulbs removed, with a test light that is connected to a known good ground, if all the correct wires light the test light then run a ground jumper wire to the sockets and see if that fixes your problem. I worked on an old chevy years ago that if you put the trans in reverse (manual) and tried to shut it off if would keep running until you took your foot off the brakes, the brake light power was back feeding through the reverse light circuit directly to the ignition switch,the box had lost it's ground, new ground wire and all was good.

 

Thanks for your explanations renegade. I believe you are right, and I don't believe the wires Crossed though. Because There are 2 plugs 1 from the the truck Itsself, And one coming from the truck bed. And they are both identical. But I believe the wiring inside is different because the truck is 2005 and the bed that I swapped his 2008. Also there is one yellow wire it is cut and sticking out it's not connected to anything that's coming from The bed harness I don't know what that is is just sticking out and it's not connected to Anything. I think someone previously played with the wires and cut That Yellow wire off. I just grounded the truck directly from the battery to the rear of the truck to the frame. And still no luck. Next thing I'm gonna do Is repin the wires in the harness. And I don't know what is the yellow wires for that sticking out from the harness wire loom. When I trace the wires going into the taillights, There are 5 wires but with the yellow wire the Total is 6. So, I don't know, If the problem is the yellow wire that is not connected to anything.

2005 F250 Powerstroke 6.0 DieseL

 

Finally fixed all my tail light flashing backwards issues. The harness plugs were wired differently because My truck is 2005 and the bed that I swapped on Is 2008. I did some test lighting and I changed the pins around in The plug And there you go they Work correctly Now.Thanks for all the help.

2005 F250 Powerstroke 6.0 DieseL