Fog lamps dont work i check fuses and relay the switch shows the fog lamps are on

The most likely cause is a 'short' in the wiring. Remove the light fitting and take a good look at the connections on the actual light fitting. Look for dirty or damaged parts. Check the wires and the connector blocks are clean, shiny and are not damaged. Then check the light fitting itself for damage. Check the seal where the light fitting fits against the bodywork. If moisture or water is getting past it can affect the lights.

System Description EKS0058X Control of the fog lamps is dependent upon the position of the combination switch (lighting switch). The lighting switch must be in the 2ND position or AUTO position (LOW beam is ON) for front fog lamp operation.When the lighting switch is placed in the fog lamp position the BCM (body control module) receives input signal requesting the fog lamps to illuminate. When the headlamps are illuminated, this input signal is communicated to the IPDM E/R (intelligent power distribution module engine room) across the CAN communication lines. The central processing unit of the IPDM E/R controls the front fog lamp relay coil. When activated, this relay directs power to the front fog lamps. OUTLINE Power is supplied at all times ? through 15A fuse [No. 43, located in the IPDM E/R (intelligent power distribution module engine room)] ? to front fog lamp relay, located in the IPDM E/R (intelligent power distribution module engine room) ? through 15A fuse [No. 34, located in the IPDM E/R (intelligent power distribution module engine room)] ? to CPU (central processing unit) in the IPDM E/R (intelligent power distribution module engine room). Power is also supplied at all times ? through 50A fusible link (letter f , located in the fuse and fusible link box) ? to BCM (body control module) terminal 55 ? through 10A fuse [No. 21, located in the fuse block (J/B)] ? to BCM (body control module) terminal 42. When the ignition switch is in ON or START position, power is supplied ? to ignition relay, located in the IPDM E/R (intelligent power distribution module engine room) ? through 10A fuse [No. 1 located in the fuse block (J/B)] ? to BCM (body control module) terminal 38. When the ignition switch is in ACC or ON position, power is supplied

check fuse 19 in underhood fuse box. Check for battery voltage coming into the MF switch on the red/light green wire. Then check for battery voltage on the white/yellow when you turn on the fog lamps. Next, check for battery voltage on terminal B16 in the relay socket after pulling the fog lamp relay

Switch?

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.

I have a 2004 f150 xlt triton. I couldn't figure out the how to turn on the fog lamps and the manual was not helpful.

Solution: turn the light switch all the way to the right and pull the switch (out) towards you. Push switch in and it turns off. The manual says to turn switch all the way to right but doesn't say to pull switch out.

i dont think current wiring harness is set up for fog lights but fuse box should have a spot for relay and fuse (although it may or may not have metal leads installed) if your getting parts from ford i ask them if they have wiriring harness for it
if you decide to wire them in yourself i would HIGHLY recomend u put a relay in the system if you dont you will have to use bigger wire tho the whole sytem. with a relay u only have use the bigger wire from relay to lights. You will also have to use a heavy duty switch u will burn up factory switch if dont use a realy

Check grounds wires and also there should be a fog lamp relay probably under the hood.

My guess is you have a corroded wire (that has shorted out the connection); known problem for this vehicle.