On a 1995 Ranger, no tail lights. Have changed the bulbs, checked all fuses, replaced the headlight switch. Checked the plugins under the cab and the back left corner of frame--ok. Not getting any power to the sockets for the tail lights. The headlights, brake lights, and turn signals, and back up lights work. Don't believe it's a grounding problem. I don't see any cut, frayed, or worn wires. Am at a total lost of what to do, any suggestions?

 

You are going to have to buy a test light or a voltmeter. If you don't know how to use one, buy one and we will walk you through it.

Ford most of the time used brown for the running/tail-lamps. This wire will be common to both rear tail-lamps and the license plate lamp. You already know the lay-out, since you have gone over the truck already. Pick an easy spot(harness plug, tail-lamp socket, etc.) and unplug the harness. Find the brown wire and with the headlight switch on, check for voltage on the brown wire. Just make sure you have a good ground on the test lamp or the black lead of the meter. If you have voltage, then work your way to the tail-lamps checking for voltage. If you don't, work your way back to the headlight switch itself. You can zero in very quickly to where the problem is by doing it this way.

 

Franklin2

Thanks for your help. Went back and retested the plugs once again with a test light. I had overlooked the solid brown wire. The problem was the plug itself, not the socket, at the back of the truck. Mystery solved, thanks to your help.

 

I am having the same prob with my 97 f150. Seabrez, could you be a little more specific about what you did to fix the prob?

Franklin, could you tell me how to work the meter?

Thanks.

 

You can buy a fairly cheap meter for checking lighting circuits and such. If you want to start checking sensors and voltages on the computerized fuel injection, you should buy a more expensive digital meter.

Depending on the meter you buy, you will have several ranges and buttons. Make sure it's on DC if you have that option, and select the correct voltage range if it's not auto-ranging. Select a voltage range that is a little higher than what you expect to read. For example if you have a 0-2 volt, 0-20 volt, and 0-200 volt, the 0-20 volt range will give you the best reading for around 12 volts. Just to make sure everything is set right, take the meter and put the red lead on the positive battery terminal, and the black lead on the negative terminal. You should have something in the neighborhood of 12 volts on the meter.

Once you have verified the meter is working, find the correct wire for the problem circuit. In the case above, it was the brown wire.

The most obvious place to check for a rear lighting problem is at the rear lights themselves. Take the light housings out and take the bulb out. Turn the running lamps on, and carefully try to put the black lead on the little brass tab on the upper edge of the socket(ground) and carefully touch one of the brass contacts in the bottom of the socket. You should get a reading when touching one of the contacts in the bottom with the red lead, with the black lead on the side contact. Sometimes this is a little hard to do and you need 3 hands. A helper can be handy, or a meter with alligator clips can sometimes be helpful.

If you get no readings, go up and turn the key to run, and turn the turn-signals on. Go back and read the bulb socket again. Hook the leads the same way, and one of the contacts in the bottom of the bulb should give you a voltage(it may or may not flash with the bulb not installed).

If you get nothing at the socket, then work your way up the driver's side frame till you find a disconnect plug. If you are concerned with the brown wire, then disconnect the plug, and test for voltage on the brown wire going to the front, with the headlight switch on the first notch. Make a good clean spot on the frame to put the black lead on, and take the red lead of the meter and probe the plug where the brown wire is located, looking for 12 volts.

I don't know if I explained it well enough, so write back if you have any more questions.

 

emnrich

Franklin2 explained the procedure the best.
Be sure to locate the brown wire. At first, I had tested the wrong wire. (It had a stripe). I located the brown wire when I opened up the casing or jacket cover on the wire bundle to the back plug-in. There I discovered the brown wire. Once it was located, I retested the tail light socket with an ordinary test light. No power. But before replacing the socket, I followed the wiring to the first plug-in from the socket. No power to the brown wire. Followed the wiring to the next plug-in under the cab. It had power. So the problem was with the plug-in located at the back of the truck. To fix the problem, you should probably replace the plug-in. If you need help replacing something, and not sure how, Franklin2 will be able to help. He's better qualified in the area than I am. I personally did some rewiring.