No voltage to fog lamps

[Shadowranger]

Hello all, fog lamps recently died and I have replaced them with smaller ones for the Mustang (due to an order mixup) and have found no voltage thru the wiring to them. All other lights works, brake, running, etc. I've cut the factory terminal off the old fog lamp harness to expose bare wire thinking the harness plug was bad. Still no volts. All fuses appear to be intact and if one was bad, wouldn't some other lights not work? So, any idea where to look?
I'm not good at tracking down shorts so if I can't find the problem it's off to a shop. 2001 Ranger XLT 4x4 4.0 V6..thanks

 

[Dirtman]

The fog light switch itself is a common failure point.

 

[RonD]

In 2001 Ranger

In Engine bay fuse box is a Fog light Isolation relay(added in 2001) AND a Fog Light Relay, and fuse 31 is the fog light fuse

When low beams or high beams are on the Isolation Relay turns off power to Fog Light relay

Parking lights can/should be on

Fog light switch in the cab is the GROUND for fog light relay

Turn on Park lights

Turn on fog light switch

Pull out fog light relay and put it back in, should hear/feel it "click" each time if its working

Isolation relay
Turn on head lights
Pull out and put back in Isolation relay, it should "click" each time

The Isolation relay powers the coil on the fog light relay, when head lights are OFF, fuse 33
The dash switch grounds the coil on the fog light relay

 

[Shadowranger]

Thanks Ron. Will do some checking tomorrow.
Dirtman, do you mean the headlight switch? there is no other fog lamp switch...that I know of never had an owners manual for this thing.

 

[Dirtman]

Thanks Ron. Will do some checking tomorrow.
Dirtman, do you mean the headlight switch? there is no other fog lamp switch...that I know of never had an owners manual for this thing.

If the fog lights were factory installed they should not come on with the headlight switch, they should have a separate button on the radio bezel as shown below.

If you don't have that switch it's very likely your truck did not originally come with fog lights and someone simply added them on at some point. In which case you kinda gotta track down whatever they did to wire them in. Could simply be a relay tied into the low beams (that's how I wired mine).

 

[sgtsandman]

Some of the Ranger models have the switch incorporated into the headlight switch. You have to pull the switch to turn the fog lights on and push it in to turn them off. My 2011 is like that from the factory. I know earlier years had that setup as well but I don’t know the years involved. I suspect it be came available that way in 1998.

 

[Dirtman]

Some of the Ranger models have the switch incorporated into the headlight switch. You have to pull the switch to turn the fog lights on and push it in to turn them off. My 2011 is like that from the factory. I know earlier years had that setup as well but I don’t know the years involved. I suspect it be came available that way in 1998.

 

[Shadowranger]

Well, you guys have solved my problem...it does in fact have that switch you posted. I always wondered what it was. But when I turn on the headlights they were always on but when I turned on brights they switched off, so I though that's how they worked. Checked today and that switch must have been turned off because there is voltage to the wires now. Now I'll try pulling the switch and see what happens.
The old lamps were pretty much done, faded glass, one worked at times while the other didn't. And the truck had been originally registered in Michigan or Minnesota with the salted roads so it was their time. I could not get either to light up on the bench after removing them. The new ones get connected tomorrow.
The truck doesn't get driven much especially at night so it hasn't been a pressing issue. But thanks for the replies...and for making me look, well, not stupid, just uninformed..

 

[sgtsandman]

The fog lights are meant to under cut weather and road glare and serve little to no purpose with the high beams on. That is why the fog lights shut off when you turn on or flash your brights. Also, the fog lights are meant for operation below 35 mph. Because of the way they project light in a wide and short pattern, they can cause you to look closer to the front of the vehicle in stead of farther away. Thus possibly missing some sort of hazard on the road, especially at higher speeds.

 

[Shadowranger]

If the fog lights were factory installed they should not come on with the headlight switch, they should have a separate button on the radio bezel as shown below.

View attachment 62996

If you don't have that switch it's very likely your truck did not originally come with fog lights and someone simply added them on at some point. In which case you kinda gotta track down whatever they did to wire them in. Could simply be a relay tied into the low beams (that's how I wired mine).

Got the new fog lamps in and working great. But, stupid question...what is the knob above the fog lamp switch?

 

[Dirtman]

The power outlet...

 

[fastpakr]

Some of the Ranger models have the switch incorporated into the headlight switch. You have to pull the switch to turn the fog lights on and push it in to turn them off. My 2011 is like that from the factory. I know earlier years had that setup as well but I don’t know the years involved. I suspect it be came available that way in 1998.

My '99 has the same fog light switch configuration as Dirtman's photo. No idea when the change occurred, but sometime later than '99.

 

[Shadowranger]

Thanks, Dirtman