2002 Thunderbird Left fog lamp not working not bulb problem. How to I find Problem?

There are several things that can cause your fog lamps to not work. The fog lamp circuits need to be diagnosed. Your entire fog lamp circuit can be tested at the plug for the fog lamp relay located n the relay box.

PIN 5 on the relay should have battery power at all times. This power comes from Fuse #43 (15 Amp) in the fuse and fusible link box in the engine compartment. If there is power at this pin, the fuse and the circuit between the fuse and the relay is good.

PIN 3 on the relay goes to the fog lamp bulbs. There should be continuity to ground through the bulbs on this pin. If you have continuity to ground, connecting a jumper wire between PIN 5 and PIN 3 should make the fog lamps come on unless there is a short circuit to ground, which will cause Fuse #43 to blow. If there is no continuity to ground on this pin, the problem is either that BOTH fog lamp bulbs are burned out or there is a break in the wire between the relay and the bulbs.

PIN 1 Is the battery power for the primary coil in the relay. This power comes from the headlamp switch and power is only supposed to be present here when the headlamps are on and the dimmer switch is on LOW BEAM. If power is not present at this pin, the problem is a bad headlamp switch or an open circuit between the headlamp switch and the relay.

PIN 2 Is the control circuit for the primary relay coil. The control circuit should have continuity to ground when the fog lamp switch is set to the ON position. If there is no continuity to ground with the fog lamp switch on, the problem is a faulty fog lamp switch, an open between the relay and the fog lamp switch, or an open between the fog lamp switch and ground E37 (right front of engine compartment) and ground F7 (left rear of engine compartment) Please note: This circuit has redundant grounds....if one ground is not making good contact, the other ground can still make the circuit work.

PIN 4 on the relay is not used.

If all of the circuits/pins are working as described above, replace the relay.

That is pretty much it... That is all you really need to know to get your fog lamp circuits diagnosed. Let me know if you need further assistance.

If it is a double filament bulb, try to rotate by 180 degrees in base, since there is a difference in power and touch of the bottom pins

First of all, did the vehicle previously come with fog lamps? I'm assuming it didn't. Normally, each YM (Year/Model) Hyundai wiring harness is complete for every feature which might be included with certain trim specifications. However, you probably don't have the multi-function switch which has the 'Fog Lamp Switch' on it (Left Hand Turn & Parking/Headlamp Switches). However, the wiring for the fog lamps is probably there, you just need the multifunction switch which contains the fog lamp switch. The illustration attached shows where the wire harness plugs into the fog lamp bulb. This connector may be taped up in the wire harness out of the way (since I'm assuming the vehicle didn't originally come equipped with fog lamps).

One fuse control both of them, that means the bulb are the for the right fog lamp is disconnect and possibly the bulb in the right lamp is blown...

on the back side of the fog lamp turn the connector to the left this will release the light from the socket pull out the old bulb and put back in turning the light clockwise to lock into position

First remove the driver's side fog lamp plastic cover out from front bumper. After that you will find torx socket head panel screws from fog lamp. See picture below:

Notes FOG LAMP BULB REPLACEMENT - FRONT

REMOVAL PROCEDURE

1. Remove the front bumper fascia deflector.
2. Disconnect the electrical connector from the front fog lamp bulb/socket. CAUTION: Refer to Halogen Bulb Caution in Service Precautions.

1. Rotate the front fog lamp bulb/socket counterclockwise to release.
2. Remove the fog lamp bulb/socket from the front fog lamp assembly.

1. Install the fog lamp bulb/socket to the fog lamp rotating clockwise until fully seated. CAUTION: Refer to Halogen Bulb Caution in Service Precautions.

1. Connect the electrical connector to the front fog lamp bulb/socket.
2. Install the front bumper fascia deflector.

Well, these are the steps and I will post the pic here in a second...looks like 2 screws...but like I said, you can see the picture for direction on this.


Remove or disconnect the following:

Front turn signal lamp

Connector

2 screws

2 claw fittings

Fog lamp assembly

Fog lamp bulb as shown

Fog light unit

To Install

1. Install or connect the following:
   • Fog light unit
   • Fog lamp bulb as shown
   • Fog lamp assembly latch the 2 claw fittings and 2 screws
   • Connector
   • Front turn signal lamp

Trying to post the pics now....

there are a couple of screws in the front of the fog light that will remove the lense so you can replace the bulb.

Yes, you can replace just the bulb. A local auto parts store may be able tell you which bulb you need or you'll have to pull the bulb out and take it in.