My fog lights, parking lights, and instrument cluster lights all stopped working at once. I referred to the fuse diagram in my owners manual and then checked the involved fuses. All of the fuses appeared to be in working order. As unlikely as it would be that all of those bulbs stopped working at the same time; to be thorough I checked the bulbs. Again, all of the bulbs appear to be in working order. About the time that this happened I had just installed flush mount LED work lights in the rear bumper. I ran a relay and an inline fuse, as I do with all accessory lighting. The lights worked, however seemed much dimmer than they should have been. I suspected a bad ground, and grounded them directly to the rear bumper (originally, I grounded them to the trailer light harness' ground wire). After grounding the lights to the bumper, they became much brighter. Job done, or so I thought. The next day I noticed the lack of fog, parking, and instrument cluster lights, additionally the LED work lights which had worked the night before no longer work. I highly suspect that the two events are related. My headlights (hi and low) both work, as well as my reverse, brake, turn/hazard lights work. ALL of the lights in my truck are LED, and prior to installing the bumper lights functioned properly.

Any ideas or suggestions?

Thanks!

 

What YEAR Ranger?

Main light switch is a common issue on all vehicles and it powers parking lights and dimmer module separate from head lights
Not sure on fog light wiring without the YEAR of the Ranger

Parking lights have separate grounds front and back, and dash lights also have 3 or 4 separate grounds to firewall, so probably not a ground issue unless its from battery ground and then head lights would also be effected

 

My truck is a 99 XLT. I replaced the headlight switch with a junkyard unit out of a 99 Explorer. The dimmer switch is different therefore I was forced to leave my original equipment in. I'm still having the same problem. I don't have running lights, tail lights, instrument lights, or fog lights. I have checked the fuses (both in the cab and under the hood) and all were intact.

Does anyone have anyone have any ideas? Thanks in advance for the help!

 

In 1999 there is a Parking light relay that powers parking lights, of course, but also powers the dimmer(so dash lights)
Fuse 11 in engine fuse box powers the lights and the relay, the main light switch turns on this relay

I assume you have keyless entry?

If so then it has the Park light relay to flash the lights when you lock and unlock the truck, and I assume again that this doesn't happen any more, the flashing lights

If Fuse 11 tests OK then you will need to find that relay, and I am not sure where Ford put it in 1999
It might be in the cab relay box under the dash above the gas pedal, it face drivers door and its back is to the radio, it has a black or blue plastic cover, there will be 6 to 8 relays inside

There can be another relay box in the engine bay on engine side of rad support, black plastic cover, only has 3 or 4 relays inside

Wiring diagram below

 

@RonD , thank you very much for the information! Yes, I do have keyless entry and again yes- the lights no longer flash when I lock the truck. I will check it out and report back.

 

I, or more accurately my significant other fixed the problem. She was convinced that it was a bad fuse, despite all of the fuses appearing to be intact. So, she ordered replacements, and we replaced every fuse (both under the hood and in the fuse block). Wouldn't you know it, she was right. I begrudgingly admitted defeat and ate some crow. But on the up-side, the Ranger is in tip-top shape again!

 

Well glad its working again

Shotgun approach can work, so we see here