got pulled over tonight because my tail lights aren't working. WTF!!! the headlights work, back-up lights work, brake lights work, hazards work. any idea why the tail lights won't come on when i turn the headlights on?

 

I assume you have already checked the fuses. You may want to check your headlight switch. My mom's crown vic did the same thing and a new switch fixed it right up.

 

if the headlight switch was bad, wouldn't that make the headlights not work also? i found a fuse under the hood that was taped up and the # 2 fuse (20A) was blown. replaced it and still nothing. any idea what that fuse was to?

 

According to the ford fleet website #2 under the hood is the air bag diagnostic monitor. My mom's headlights still worked fine when her switch went bad.

 

...that really sux!! i jus looked it up on the NAPA site and it says its $91!! does that sound about right? btw, i also noticed my tag lights don't work either. could that also be caused by the headlight switch?

 

does anyone know which fuse controls the tail lights? i don't have the owner's manual to tell me.

 

Downlaod a manual at :
https://www.fleet.ford.com/

Power Dist Box ( under hood ) Fuse # 7 is the parking and tail lamps.

Question, do the front parking lamps work ? This is all the same circuit / fuse.

If the brake and reverse lamps work, you know the ground ( circuit 57 / black => White 10 AWG under the truck with the trailer tow adapter ) is good.

The tag lights are on the same circuit ( brown # 14 ).

Check the fuse first. The next step is to work backwards ( if the front is working correctly )

 

"The next step is to work backwards ( if the front is working correctly )"
i checked fuse # 7 under the hood. it looks ok.(replaced it anyway). still nothing. the parking lights in the front are working. what did u mean by "work backwards"?

 

start from the front and work your way towards the back of the truck.

did you check all the other parameters that he listed?

would the bulbs have anything to do with it?

 

Ok, good info. The front marker lamps working means that the fuse and the main headlamp switch are good to go.

Dug up the EVTM page for the 1997 Exterior Lamps :


This means to C158 in the driver's kick panel is good, and splice S115 is good ( this is where the circuit branches to the rear of the truck.

I guess I should have asked, are the brake and reverse lights working at full wattage ( i.e. not dimmer then normal ) ?

A quick test is to check the bulb connector in the rear tail light for +12v when the brakes are on with the red lead on Light Green w/ Orange Stripe and the black lead on the black.
If this is +12 V DC, then next is to turn on the parking lamps, and test with the red lead on the brown wire, and the black lead on the black ( same as above ).
While you are at it, check for a brake light at the 4 pin trailer tow adapter, as well as the parking lamps, if / when you move on to step 2 above.

You could also eye ball the rear tail lights to the CHMSL, but this is somewhat subjective, and may not give accurate results.

I am looking for a missing ground, and maybe the brake lamps are using the parkign lamps for a derived ground ???

If not, we are looking between the driver's side kick panel, and the rear of the truck.