F-250 Super left rear blinker and brake light not working. Need help.
Left rear blinker and brake light not working. Front left blinks fast. Running lights work OK. Factory installed tow controller. Trailer brake and blinker on left side pin do not work either.
I get no power on left blinker trailer pin or in light socket on truck. Bulbs are good and even replaced. Wiring harness looks excellent everywhere. Have checked fuse under dash, it is good. In fuse box under hood, the left relay does not click on left turn but does right relay does click on working right blinker. Also stabbed wire at rear of truck before it splits and no power there for blinker or brake on left side. Also checked grounds, they are OK.
Under the hood in fuse box, I checked power in trailer relay socket for left side. One pin of socket is solid on, other pin sockets are dead. The right side relay has one socket solid on and another blinks with right blinker as it should. Fuse there is also good.
I am inclined to think it is either a bad (open) wire on the end of a wire harness after fuse. The open wire thing is hard for me to believe because harness is intact and has not been disturbed at all.
Any suggestions would be appreciated. I am at my wits end on tracing this. Can the blinker switch on steering column go bad and cause this problem? Can one test the blinker switch on column or bypass to check if wiring is good?
It sounds like you have replaced just about everything. I had this problem with an old pontiac and it turned out to be the actual blinker switch on the steering column. If all your flashers are good, bulbs are good, relays are good, it may be the actual blinker switch
2011 ford f250 just found a broken wire on the firewall (rubbing against the steel)under the intake box, was the problem with left rear turn signal !
check the plastic wrap on the wire harness that feeds the light and look for a crease. remove plastic wrap to a point below crease. solved this problem on both my 2000 and 2005 f250s after changing left rear brake light several times.
So what was the fix? I have the same problem on a 2011 f350
i have the same problem on my 2011 f350 lariet
Ended up taking to dealer. Could not find the problem myself. Cost about $800 to fix a bad wire in harness and of course not under warranty. Big ripoff.
I'm gonna take mine in and flash modules. 100 bucks. Hope it works. Where was your broken wire at? By chance was it in between the two fuse panels?
Didn't find out where it was bad. Sorry.
Just repaired the same problem on an 07 and found a bad connection in the harness plug under the coolant tank below the fuse box
I just had the same problem. 2011 F-450. Chased it all the way back the the body control module. Replaced the body control module and it solved my problem. Hope that helps
My truck is have break light take food out the pedal not light no we're back not iven if I on the switch
I cleared the codes in the body control module and the left rear started working.Don't know if the code will come back or not.
I have this problem on my 2001 f350 and can’t seem to find a fix. I need help
I also have the same problem on my 2011 F250 right rear brake light and turn signal not working please help
Luis did you find anything my 2011 is having same issue no right blinker or turn signal noticed my cab brake light isn't working either hooked my trailer up and no running light or brake and turn on it either on the right side
sounds like you need more blinker fluid
Change LIGHT BULB!!
I had same problem. Drove me insane. Figured mine out to be the socket the bulb plugs into was bad. Hope this helps someone
I too had the same problem. I spent over four months trying to self diagnose and repair with no luck. Mine was a left rear turn/brake light. I had full running lights and reverse lights. Just no turn light or brake light. There were no warnings on the dash. My front turn light and mirror turn light worked fine, except that they hyper flashed. I changed the bulbs, the fuses, light sockets, and even changed out the turn signal control arm module. Nothing fixed the problem. Until today...here's what worked. I took it to a trusted mechanic, Christian Brothers Automotive, and they agreed to hook it up to their computer to see if there was an internal error code. Even though there was no warning light on the dash. Turns out that the Body Control Module (BCM) will kill power going to a circuit when it senses a short in the circuit. It will throw an error code and will not allow the circuit to run until the code is cleared. I figure I had a short in my turn signal control module, being that the functionality of the turn light would go in and out during use. Once I changed that part my problem was fixed but I had to get the code cleared. Find yourself a mechanic that has the right diagnostic computer that can see into the BCM error codes. Have them clear any codes and see if your problem goes away. Mine did!
I just resolved the same issue on my 2011 F-350 . I found the wire for the brake/turn had rubbed the tow bar frame and shorted. I fixed the wire then checked fuses and wiring all the way to the BCM. All were good. I used ForScan to check for errors and reset all the DTC's then reset and ran a self test on the BCM. That is what fixed it.
Guytron can you explain where the tow bar frame is? Having same issue and can not find a break in wire anywhere
it look like the fuse box under the hood is bad
I found a shorted wire that was out out insulated wrapping not far under left taillight. I’ve re-wired + got BCM reseted at my local garage that had the tool to reset it. Thanks for all that posted, it really helped in the diagnosis.
I see some exposed wires on my trailer.. My bloothtooth obdii dongle reset didn't work, i'm going to try using forscan tomorrow. if that doesn't work, i'll try resetting the battery.. if that doens't work i'm not buying any expensive computer, i'll figure out a way to use relays and run my own wire from my front turn signal that works and my brake light system.. I might buy one of those trailer 4 wire to 3 wire conferters if i need to.. actually i think i have a spare one already
if anyone in the dc area needs theirs reset via forscan i'll do it for $20 instead of you paying hte dealer a hundred
