redraiderford

Last night after doing a speaker test with my radio i ended the test as stated. When i went to start my truck the radio read "low battery." I tried to start the truck and all of a sudden the horn was randomly honking and the radio lights and ac lights were flickering. I disconnected the negative terminal just so I could stop the honking and figure out what was going on. I searched forum after forum trying to find what was wrong but couldnt. The only thing that would get the honking to stop was to put the key to the "on" position and disconnect the negative terminal and then reconnect the battery so i could jump it. Today, after jumping the truck again I drove out to SAMs and picked up a new battery as AutoZone and SAMs had both read the battery and told me it was dead. The truck fired right up with the new battery but it started honking while we were putting it in. My boss and I were able to find the fuse for the horn and remove it to stop the honking. The lights still flicker and you can hear the actuator for the horn trying to honk. Once i start the truck and drive the lights become fine and the tapping stops. Has anyone had this problem and fixed it without taking it in. Luckily my extended warranty will cover this problem after a deductible. It is just a pain to take the truck in, leave it, and not have a vehicle to drive. It is a 2007 F150 Lariat with 85000 miles. Any help would be greatly appreciated before I let someone else fix it.

vintageman

I had a similar thing with my old 99 expedition. My son in law fixed it while i was deployed. I think it turned out to be either the clockspring or the security module. I will have to ask him to see if he remembers. I do remember that it was pretty annoying as it usually only went off in the middle of the night. Good luck and I will try to find out as soon as I can.

screwf1fidy

Sound like something with the security system

redraiderford

Well it seems to be fixed for now. After taking the fuse for the horn out, and leaving it out for about a day with roughly 15-20 starts without any tapping or light flickering, I put the fuse back in and nothing! I could not get the horn to go off or the lights to flicker. I tried honking the horn and locking it twice to honk, still nothing. I tried everything that had caused the strange honking but I could not replicate it. I did switch to a new key and battery in the key fob. I do not know exactly what fixed it, but I am happy that it has stopped.