Hi guys, did a search and came up empty so far. Still searching though.

The rear tail lights (both) do not come on with the headlights.

The reverse lights work.

The T/S and four-ways work.

The front parking lamps work.

Here is the kicker-the brake lights work!

I replaced the tail lamp bulbs, greased them, and didn't see any corrosion. I also checked the fuse-it is good.

I assume that since the brake lights are working, there should be nothing wrong with connector-right?

The only thing that I can think of is the headlight switch has gone bad.

Has anyone here ever encountered this before?

 

Have you checked for continuity of the wire that feeds the tail lamp filaments? The wire that feeds the other filament (Brake, turn, 4 way flashers) is obviously OK.

 

Are we talking about your 94 Ranger????

If so & all the other rear lights are working ok, including the license plate lamps, it would seem that the light switch is likely ok, as it has to provide power to splice #S414, to power the license plate lamps.

The tail lights brown wire, coming off this splice & going to connector C401 & then to splice #416, which splits the power feed to the left & right rear parking lamps, should be on your suspect list.

So with the parking lights on, go to either rear parking lamps socket brown wire & begin tracing it forward, to find splice S416 & probe it for 12 volts to ground.

If you find power at splice 416 , then there is a wiring probem between this splice & both the left & right tail light sockets. Not likely imo.

If you don't have 12 volts at the splice, continue on to connector C401 which feeds power to the splice you just checked & seperate it & probe it for 12 volts to ground. Connectors are common problem spots, so check for corrosion of the pins & sockets, bent pins or sockets, or cut wires.

If you have 12 volts to this connector, then you have a wiring open circuit problem, between this connector & splice S416, you just probed.

If you don't have 12 volts at this connector, you'll have to continue foward to splice S414, which also powers the license plate lamps, which you know are working.

So then, you likely have a wiring problem between this splice (S414) & connector C401.

If the license plate lamps aren't working, you'll have to continue foward to connector C118, disconnect, inspect & probe it, for 12V to ground.

If ok, then you have a wiring problem between this connector & splice S414, which feeds your license plate lamps & tail lamps.

If no power to this connector, then continue foward to splice 164, which also feeds the front left & right side lghts, which you know are working, so you likely have a wiring problem between this splice & connector C118.

Hope this step, by step check doesn't read/sound too confusing, just take it one step at a time, begining at the tail lamps & working foward.

If the splice & connector numbers make it sound too confusing, forget the numbers, just look for the splices & connectors in the order I've listed them, beginng at the tail lights & tacing the brown wiring foward.

Let us know how it goes.

 

Thanks pawpaw for your tutorial.

Yes, this for my '94 Ranger. However, the license plate lamps also do not come on. Sorry I missed that in my first post.

I will check it out today and see what I come up with. BIG thanks for the wire color info on the tail lamps.

I'll post back with the results.

On Edit:

I forgot to mention that yesterday I removed a taillight converter at the connector that feeds/splits the power to rear taillamps. It is basically a T-connector with matching ends for the factory connector. At the other end was a connector that I assume was to plug into a trailer harness. We got some heavy rain the other day and I suspected that the open end of the tail light converter might have absorbed some water. I removed it and reconnected the factory connectors, but the lights still didn't work. The connections looked good to me (pins/sockets) and I could see some grease was in there.

 

OK, I checked for continuity at the connector (C401?) that is right before the splice that feeds both tail lights. I did NOT get any continuity at the brown or Green/Orange wire.

I followed the wiring to the gray connector underneath the hood on the splash sheild (C118?), right under the power booster. I checked both sides of the connector with a test light. It seems to be good here (the test light glows).

So it would appear I have an issue between these two connectors. I looked along the frame rail, but didn't see any other connectors between these two-is this right? I'll keep probing front to back until I find something.

I hope to get this resolved ASAP, because I don't want to drive home 30+ miles w/o tail lights (raining/dark)

Thanks guys!

 

Ok, so I just noticed that the LH license plate lamp works with the parking lights on.

I checked the brown wire about half way back the truck and it seems fine. When I went to check it further down, just behind the axle, there were 3 brown wires! I just can't see whats going on here, oh and its raining too.

Did I mention I really dislike electrical gremlins?

 

OK, I'm not clear what kind of measurement you made at the taillight connector C401.

"Continuity" to me, indicates you made some kind of resistance (ohms) check, not a DC Voltage check.

With the light switch on, you need to put your multimeter on the 20 Volt DC scale & measure the Brown wire to chassis (ground), voltage all along the connectors & splices way forward. You should have battery voltage (12 vdc), betwen the Brown wire & ground, if the connections are good.

The stop light filiment wires aren't Brown & won't have voltage on them unless someone steps on the brake pedal, or you turn the emergency flashers on. So trying to get a reading between the Brown wire & what ever color the brake light wires are, won't work & will confuse you.

So just concentrate on a DC voltage reading, between the Brown wire & ground, a you go.

You said all the fuses "looked" good, but were they???? Did you measure voltage to ground, on both sides of the fuse????

 

When I checked the continuity, yes it was an ohm resistance check, basically just looking for no breaks in the wire. I will check the DC Volts. The brown wire is the rear tail lights right? The brake lights work fine.

How do I check the to see if I have 12V at the fuse? What do I use as the ground? Sorry for all the questions, electrical stuff is not my forte.

Also, why is only one license plate light working? Aren't they coming from the same wire that's split? Both were working fine until this issue happened a day or so ago. Thanks again.

 

OK you had posted while I was replying, so now you have one license plate light on!!!!

Thats good, as it indicates the light switch, fuse, splices, wiring & connectors are good all the way back to the splice 414, which the license plate & tail light power split.

So your taillight power problem has to be between this splice & the lights.

So as I said, go back to the taillight connector C401 & check for DC volts (12v), from the brown wire to ground (a clean bright unpainted, uncoated metal point) & let us know what you find.

I wonder if in removing the tail light converter, you've disturbed something, or maybe hooked the tail light connector up to the trailer harness connector, or something like that????

Were the tail lights working ok before you installed & removed the converer????

 

Thanks for your reply pawpaw.

I just bought the truck a few weeks ago, so I didn't know the tail light converter was even there. When the tailights quit working, I saw it on there. It just fit between the two factory connectors (C401). I initially removed it to see if it was causing the problem-no luck.

I will check to see how much voltage I am getting there. When I probed the brown wire at the connector (front side) using a test light-it didn't light.

 

OK, well lets forget about the converter, as it isn't in there now, right????

Yes the tail lights power wire color is Brown. So, with the light switch ON, check for 12 vdc, between the C401's Brown wire & ground & see what you get.

You know that you have power to splice 414, because one of the license plate lamps is working, so if you don't have power to the Brown wire on C401, the problem is with the Brown wire, between C401 & Splice 414.

If you have a 12 volt test light, it may be easier to use it, to see if it'll light up, in place of the multimeter voltage checks.

If you do any resistance (ohms) checks, be sure to remember to turn your light switch OFF, so you don't FRY your multimeter!!!!!

The Stop light wire colors are O/Lb for the passenger side & Lg/O for the drivers side.

BTW, even if you can't get this resloved before dark & driving home, just use your emergency flashers. Any port in a storm RIGHT!!!! lol

Send that rain on down here, we're about 15 inches below normal & everyhing is TRIRSTY!!!!

 

SUCCESS!

As I went back to check the voltage at the C401 connector, I noticed some tape around the wire loom about 10" back from the connector.

I undid the tape and found that someone had spliced these wires right after the 414 splice. Well, sure enough the brown wire had become disconnected from itself.

Grabbed a new butt connector, heat shrink and tape and did a quick fix. Now that I know this will probably become an issue, so when I get some time I will redo all of these wires that were spliced (they have no tape or heat shrink on them!).

Now the RH license plate light still doesn't work, but at least the tail lights do! Thanks again!

 

I was typing when you replied.

Yes, the tail light converter is gone from the equation.

We hurting for rain here is well. It rained pretty good the other day, the day my tail lights quit

Today it hasn't been much, but we need all we can get!

 

OK, good troubleshooting, way to hang in there & see the problem through.
Feels good to win one, once in a while doesn't it!!!!

 

On the pasenger side license plate light that doesn't burn, pull & check the lamps filiment, it may be burned out.

If it looks ok, try your test light, or multimeter on the 20 VDC scale & measure for 12 vdc to ground, at the sockets brown wire contact. If things are ok, the multimeter should show 12 volts, or the test lamp should light up.

if you don't have 12 volts at the lamps socket, check the brown wire back to splice 414.

If you do have 12 volts to the lamps socket, then check the right side lamps ground wire to splice 401, where the left license plate lamps ground wire also connects.
Because the left lamp is working & both lamps use the same ground point, the problem would lie between the rigt side lamps socket & this splice.