I have a 2002 F150 Lariat. my issue differs from others I've read. So, I've noticed when I turn the key off and remove them and open the door my interior lights come on as they should, but I have a ding like I left the keys in the ignition and the radio stays on, once I shut the door the ding stops and if I lock the doors the interior lights go off, but the radio does not. I've pulled the face off the radio to try and stop the power but over night the battery still is drained. I removed every fuse to find the ones controlling the ding as well as the radio. Radio is on fuse 1 ding stops when fuse 15 is removed. I don't seem to have any other issues but these. everything seems to be working fine lights and wipers ac truck runs beautifully it's just this issue when I park. it's not changed by any door I can open all door does not change.

Any ideas?

 

If it's just the radio, then:
is this an aftermarket radio ? If so was it wired in correctly ? Did the radio exist before the problem started ? were there any other electrical modifications made ?

If the ding alarm is also failing then a possibility might be the GEM. I'm not sure if the radio goes through the GEM.

 

It is an aftermarket system but it’s been the same for the last year nothing has changed. That’s part of what has me stumped is the “all of the sudden issue” there were no signs of any issues

 

I know it's an older thread but maybe someone else might find it,
It's probably the ignition switch.
Some background, I picked up a '98 XL f150 flareside, v6 manual, in 2012? for an everyday driver that sat for about 7 years in a field. Got it running and ran it for 10 years and the last 6 years driving 130 miles to another city to work during the week and drive home on the weekends. Retired last year and parked it for the most part. I try to drive my vehicles at least once a month to charge the battery and get the oil hot. So I go out one time to grab it and battery is dead, put charger on it, come back a bit later and I hear a fan running and no other lights on or door ding dinging and I hadn't put the key in yet. Put the key in and turn it to on and the dash lites light up and it will start. Turn the key off and pull it out and the fan keeps running, turn the fan off on dash and it stops. I played with the ignition with the key and still nothing. I bought some key "lube" and sprayed the hell out of it and it still didn't work. I left the battery unhooked and let it sit for a month or so until I could work on it and now -it works fine-. I assumed it was the ignition switch and was going to just replace it but now it works fine. Never had an issue with the ignition before. By the way I live in the rainy Pacific Northwest so I just chocked it up to that.

Altho now I have a brake pedal that goes half way down before it starts braking and had a hell of a time with the rabs kicking in when first driving down the driveway when hitting the brakes normally. Guessing it's the rabs module, after reading a few forums issues going to check it out. sheesh

 

Honestly it sounds like you got some shorted out wires…hate to say it, possibly due to rodents.

any time something sits a long time, it’s an invitation for a rodent hotel to pop up.

Likely it’s in a wire bundle ect. I’d get out a mirror and start looking behind the fuse box, under the dash, steering column etc, etc.

if your lucky maybe you can separate the wires and slop on liquid tape, retape etc. worse case would be cut and splice sections.