2002 Ford Taurus Door Ajar/Seatbelt light on - later dome light and side mirror lights come on when parked.
A while back, my door ajar light and seat belt light came on (usually during a heavy rain) 2002 Taurus SES (U engine). I did use the WD40 trick and it worked for a while (months), but eventually would reoccur during a heavy rain. It happened again and not rain, but this time the WD40 did not work. While driving, my door ajar light and seat belt light came on. Opening and closing driver side door did not turn it off, but opening/closing passenger side door turned it off for a short time and then came back on. After parking the car, locking the doors, side mirror lights and dome light were off - short while later, they came on by themselves. Sprayed ALL the door latches several times with WD40 - no help - removed door panels and sprayed a ton of WD40 wherever I could and still no help.
I have to disconnect the battery. When I reconnect the battery the next day, I can drive for a while, but then the warning lights come on and sometimes the door locks cycle unlock/lock. I park the car, turn off ignition and leave set - an hour or two later, the dome and side lights come on. And yes, I removed the key when I turn off the ignition. I have searched high and low on the internet and have not found a good answer - just some SWAGS and 99% of the time, the WD40 trick. Some posts on the internet allude to the Door Jamb Switch, the Door Lock Switch, the Door Lock Relay, the Door Open Warning Switch, the Door Lock Actuator, etc. However, I could only find how to replace the door actuator but no help on where the other switches or relays would be located for this problem (assuming one of them is causing the problem). My first suspicion is the Door Lock Relay, but I can't find where it would be located.
On top of this, while trying the WD40 trick, I had the A/C - heater blower fuse go (just high speed works). BTW, I had the PCM replaced back in May of this year by a Ford dealer - not too cheap $1100+.
Please answer with a solution or recommendation (other than WD40 and repeated open/close doors) not another question.
Sounds like you did your research. I think you answered your own question. The passenger side door might be the issue and looks like you will be replacing the door latch assembly. Find one at your local auto salvage yard. Better yet, have a local auto mechanic, not the dealer, search down the issue for you vs throwing parts at the car. Electrical issues are a PITA to find for even the best mechanics. Requires a lot of patience.
How do I know it "MIGHT BE" the door latch assembly? What parts comprise the door latch assembly? There are 3 switches and a relay? How does one replace something that the door construction makes access to those parts difficult without special tools? I have not found any Youtube videos showing how to replace all those parts nor have I found anything that tells me tell me the location of the door lock relay. Also, could it be the GEM - which is recommended having to be reprogrammed by the dealer. Again, please answer with a helpful solution or recommendation besides going to a Ford dealer.
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