I thought I just probably blew a fuse last night when I plugged in the boat trailer lights after pulling the boat out of the water. Of course the truck was running with the headlamps on so when I plugged the harness together it threw a little spark. Running lights work just fine. I noticed when I went to go put my blinker on it didn't work. The only brake light that works is my third brake light on the cab. I've checked every smaller fuse in the cab and under the hood. Is there anyway I could have blown every blinker/brake light on the truck except the cab brake light? Thanks for any and all the help I can get.

 

I would check fuses first.

The third brake light is pulled before the brake signal goes through the flasher relay.

 

Might be a dump question but what do you mean the third brake light is pulled before the signal goes through the flasher relay? I've pulled and tested every small fuse under the dash and hood. All of them are good. I did notice that the number 13 fuse had a 30amp fuse instead of the recommended 20amp fuse(in the cab). I don't know if this could have caused a short or not. I pulled out on tail light bulb and it is still good so I'm kinda lost on what to do. Could a bad relay cause it to not work? I asked a fella at autozone and he insisted it had to be a fuse and not a relay, but I know most of them don't know as much as they think.

 

What I got from your post.

1. Parking lamps work correctly
2. The CHMSL ( Center High Mount Stop Lamp ) works correctly.
2.1. The stop/turn/tail lamps on the bed of the truck, only the parking lamps work, nothing else ( no brake, no turn ).
3. No turn signals all the way around the truck.

Not too sure where you were going by checking every smaller fuse in the cab and under the hood., nor what the method you used to check them is.

When testing fuses, they are tested installed with a meter set to VDC and check both pins on the back of the fuse.

Questions :
1. Do your hazards work ?
1.1. Check front and rear for this.
2. Check CJB (aka Central Junction Box / Cab fuse panel) fuse #23.
2.1. This fuse is only hot in run position.
3. Check BJB ( aka Battery Junction Box / Engine compartment fuse panel ) 19 & 20
3.1. These are only hot when the brakes are on, or will pulse DC when the turn signal is on.

 

Check the tow fuse its a maxi fuse in the engine bay fuse box

 

What "Tow fuse" ???

There is a Trailer Tow Battery Charge maxi fuse and a Trailer Tow electric brakes maxi fuse, but no Tow fuse.

 

yes the trailer tow electric brake fuse is the one i was referring to

 

I looked at all the maxi fuses. They are the ones with the clear top on them that you can see the metal ring inside. The metal was unbroken on all of them.

 

All the things you got from my post are correct. I started by just pulling the certain fuses that I felt could be related to my problem in the autozone parking lot. After all of that passed I bought just a 12v test light (the one you hook the gator clip to a ground). I checked every fuse that didn't light up. Of course I know alot of them don't light up with the truck running but I checked them all anyways. Another thing I noticed that the number five fuse i believe was missing from BJB. So I installed a new one but it didn't fix anything. So I drive back home, change my front brake pads and replace one worn rotor. Drive it out of the shop with my lights on and park it. When I cut my lights off the parking lights stay on. So after scratching my head a while I pull the fuse out that was missing back out and they go off. They come on and off like normal. Put it back in, they stay off until I turn the running lights back on and they won't turn back off without the fuse being pulled. I bought the truck about 5 months ago I guess. But either way the trailer and truck lights have worked flawless up until this point.

Not sure if it makes a difference but I plugged the 4 pin trailer harness into a 7 pin to 4 pin adapter attached to the truck. I use the adapter harness just bc the my dads boat's harness is just a couple inches too short for my truck so the harness gives me the needed length to make it work. Thanks for all yalls help, I appreciate it.

 

And the flashers/hazards do not work either. Just the running lights, fog lights, head lights, and the third brake light. The in cab blinker indicators won't even come on.

 

Time to stop the guess work diagnoses. The owners manual provides a list of the fuses, no need to use a feeling that a fuse might be related. Not too sure how you can claim that the test passed without a meter or test light ( was this the pull and stare method ? ).


Actually with the truck in the run position, there are very few fuses that will not show power. These are the hot in start position only fuses. I can only think of 1 at the moment.

If it was Fuse #5 ( need to be sure of the fuse placements, not I think ) that is for the trailer tow backup / park lamps, which means the parking lamps on the trailer would not have worked. Is this the case, the trailer parking lamps did not work when this happened ?

Just a SWAG, take a very close exam of the 7 pin & 4 pin trailer tow adapters, pay attention to the back of the 7 pin for corrosion or damage.
The description above leads me to believe that the battery charge circuit is back to the stop/turn circuit, or ground it. The back of the 7 pin trailer tow adapter comes apart with a screw. There is a thread on the site here, that has pictures in it on the topic.

 

Well I solved the number 5 fuse problem. I snipped a jumper wire I seen a few months back that was from a previous owner I would presume. It ran from the passenger tail light wires to the trailer wire hookup. Not sure exactly what they were jumping but obviously w/o the fuse the trailer running lights still worked. So whatever they were trying to accomplish was really rigged. Either way I really don't think that is the problem since I've been pulling a trailer/boat a good bit since I bought it.

 

Amazingly the problem fixed itself...atleast for a little while. The work off and on now. When I turn the blinker on it either blinks properly or the in dash indicator doesn't work and I have a buzzing/humming sound come from under the steering column where I believe the flasher relay is located. I'm going to replace it pretty soon and see if it fixes it.

 

I have a 01 Ford F150. Yesterday the breaks, turn signals, and hazards quit working. Everytime I put a fuse in spot 13 it would blow the fuse.

I searched online here and was pointed into the direction of a recall on SCDS (Speed Control Deativation Switch) Recall # 05S28 as the culprit of my problems with fuse 13 blowing.

I took it into the dealership to get the recall done and of course they argued that the SCDS switch had nothing to do with my fuse 13 blowing. There was a person on here that said the dealer would say that and to tell them to look at EVTM cell 13-9 CJB fuse 13 both feed BPP switch (EVTM 90-3) and deativation switch (EVTM 31.2).

After the recall repair was complete, while still at the dealership, I put in a new 20amp fuse in spot 13 and guess what my breaks, turn signals and hazards all work now.

Thank you for you help fixing this problem for only the cost of some new fuses!

 

Glad to hear you got things fixed with the recall.

GREAT search of the site to find the info to tell the dealer.
That has to be 2 or 3 years old .