Door ajar light stays on and interior dome light stays on my 2000 Ford ranger

Principles of Operation
Interior Lighting The interior lighting is broken down into two groups: the courtesy lamps and the illuminated entry lamps. Both lighting features interact with the courtesy light arbitrator. The battery saver is also listed in this section.
Courtesy Lighting The courtesy lamps consist of the dome lamp and/or map lights. The courtesy lamps can be activated by the GEM using the panel dimmer switch, or by any ajar door. The courtesy lamps will shut off when the doors are closed and the illuminated entry feature is not active, or when the vehicle speed is greater than 8 kph (5 mph). The interior lamps will not be reactivated until the vehicle speed is less than 5 kph (3 mph) and a new door open warning lamp switch signal is received. The inputs are:

• ignition switch position

• driver door ajar switch

• front passenger door ajar switch

• rear left door ajar switch

• rear right door ajar switch

• vehicle speed switch (VSS)

The outputs are:

• battery saver relay

• interior lamp relay

The door switch doesn't go to the dome lights , the switch (door ajar switch ) is an input to the SMJ - smart junction box or body control module take your pick .
Principles of Operation
When the SJB detects a request for lighting, it turns on the interior lamps by supplying power to the lamps. The request for lighting can be an open door signal from a door ajar switch, an interior lighting on command from the instrument panel dimmer switch or an unlock command from a remote keyless entry (RKE) transmitter.
The door ajar switches are hard-wired directly to the SJB. The 2 door ajar switches are normally closed when the doors are closed. The decklid ajar switch is normally closed when the decklid is closed. All door ajar switches receive voltage from the SJB and each has its own ground circuit.
The instrument panel dimmer switch receives a ground signal from the SJB. The instrument panel dimmer switch provides variable resistance for backlighting the instrument cluster and a toggle ON/OFF function for the interior lights.
The RKE receiver is contained inside the SJB. When the SJB receives an unlock request from an RKE transmitter, it unlocks the doors and turns on the interior lamps. There could be DTC'S diagnostic trouble codes stored in the SJB ! You can not access these codes with a OBD2 code reader , need a factory scan tool .
B1319 Driver Door Ajar Circuit Failure Go To Pinpoint Test D . B1327 Passenger Door Ajar Circuit Failure Go To Pinpoint Test D . B2021 Dome Lamp Input Return Circuit Failure Go To Pinpoint Test A . B2550 Dome Lamp Output Circuit Short to Ground Go To Pinpoint Test A . B2554 Dome Lamp Output Circuit Failure Go To Pinpoint Test D . Do you know B-codes -body control .
Your best bet is to take to a ASE certified repair facility or a Ford dealer .

door sensor is bad. switch is staying closed allowing juice to interior lights. The door switch is there. have autozone or napa look up the location for you...

I have the same problem, the switch in the door is either faulty or the door latch is sticking, try spraying the door latch with WD40 and open and close your door to work it in if this is the problem it should free up the latch which hits the switch for the dome light and the door ajar light. This did not work for me I replaced the door switch with push pin switches instead.

It's where you close the door.

Check all of the door jam switch either one of them is stuck or one of them is faulty.

the problem is caused by a defective door ajar/dome light micro switch, there is one for each door, they are mounted to the door latch assembly inside the door, to replace it you must remove the door panel and the rear glass run channel, most likely the drivers door is the one that is defective since it sees the most use, they are a real pain to get out,they twist in and the old one will be a bear to remove, twist it out counter clockwise to remove from latch

You need to remove the door ajar sensors from the doors and clean and lube them. You must remove the interior door panel then remove the door latch. Then twist the switch out of the latch to work on it.

spray the door latch with WD - 40 on both doors then open and close multiple times. Sometimes they get stuck ond this help if they free up once a month should keep it away

next to the head light switch there is a roller switch. roll it down one click tell me what happens. sorry if you already tried this. good luck.