2001 brake signal lights don't work

[RazorbackB]

I am new to Ranger Trucks and new to this forum. I searched but couldn't find my problem. My tail lights work. But my rear brake and signal lights do not. I am getting a fast flash with the signal lights. I replaced the bulbs and checked the fuses but nothing. Can someone point me in the right direction?

 

[franklin2]

Fuse 3 is the left rear brake turn and fuse 7 is the right rear brake turn. These are in the underdash fuse box. Get a testlight and check these fuses, the testlight should blink when it is touched to these fuses when the signal lever is activated.

 

[RazorbackB]

Fuse 3 is the left rear brake turn and fuse 7 is the right rear brake turn. These are in the underdash fuse box. Get a testlight and check these fuses, the testlight should blink when it is touched to these fuses when the signal lever is activated.

I appreciate your help! I checked the fuses and also used a test light to check for power to them, as you suggested. The blinkers are "fast blinking," but there is no power at fuse 3 or 7.

 

[RonD]

Welcome to TRS

It most likely wiring issue if someone added their own trailer lights under drivers side rear of the Ranger, main rear light wiring harness
If the wires there have not be messed with then problem is the Multi-function switch(turn signal stalk)

Brake/turn use 1 wire for each side for rear bulbs
Front turns and dash turns are separate wires

Brake light 12volt(pedal pressed) travels from brake pedal switch to Multi-function switch and then out on the 2 wires to the rear
BUT, there is a separate brake light wire that travels to 3rd brake light on the cab, by-passing multi-function switch
So if 3rd brake lights works then brake pedal switch works

Try the 4-way flashers, they use a slightly different pathway in the multi-function switch, but the SAME 2 wires to the rear
Does Flash-To-Pass work, high beams when you pull stalk toward steering wheel, just checking functions

When you turn on a turn signal the multi-function switch disconnects the 1 rear wire from brake light wire on that side and connects it to the flasher module, and bulb starts to blink
The other sides brake light would work normally

Muli-function switch is accessed by removing the top and bottom "clam shell" covers from steering column
It has two screws/bolts holding it on, remove them first then unplug the connectors
Inspect the wires/connection
Plug them back in and check if brake lights in the rear both work now

In the diagram you will see a Dark Blue/White stripe wire is used for Left rear(drivers side) and a Brown/Yellow wire for Right Rear

If those wires get 12volt then bulb will light up if wire is OK

There is a Dark Blue/Orange wire from fuse 24 in Engine Bay fuse box that has 12volts all the time at the multi-function switch(for Flash-To-Pass)
You can use that as the 12v source and jumper it to one of the rear wires to test if wire is OK, bulb lights up
If both wires work then replace multi-function switch

And just FYI, fuses 3 and 7 in cab fuse box were only for factory trailer wiring harness they wouldn't effect rear brake/turn wires on the bed

 

[franklin2]

Ron, don't you think it's interesting that he did not get anything on those tow fuses? Even though those are trailer fuses, they still should have power on them when the signal or the brake is pushed? Does that point to a wiring problem in the column or at the bottom of the column?

 

[RonD]

Yes, that would point to multi-function switch issue

 

[RazorbackB]

@RonD & @franklin2 - thank you for your help. I plan to work on the truck today and will let you know what I find.

 

[RazorbackB]

Hello! I have been slowly working on this project. I appreciate the wiring diagrams - that has been helpful.

I replaced the brake pedal switch. Now the upper brake light works. So I have made some progress.

I also replaced the multi-function switch, but the rear brake/signal/hazards still are not working. I am getting a small voltage to fuse 3 and 7 with the flashers on. It doesn't seem to be getting the full 12 volts. The indicator moves some but not like the normal response for 12 volts.

It seems like something is going on in the rear. I checked the rear harness. It all seemed to be intact.

Do you guys have any other thoughts now that I have replaced the brake pedal and multi-function switches?

Again, I appreciate your help!

 

[franklin2]

Did you see a spot where you can unplug the complete rear lighting harness as a test?

 

[RonD]

Key off
Unplug the multi-function switch again

You will see in diagram 1 there is a light green wire on that connector that should have 12v when brake pedal is down
Test to make sure it does

There is also a Dark Blue/Orange stripe wire, it should have 12volts all the time, this is for "flash to pass" not for tail lights but its a full time 12volt source for testing the other wires
Fuse 24 in engine bay powers this wire in case you short it and it blows, 30amp fuse for headlights

Have a short jumper wire handy, paper clip can work

On the connector is a Brown/yellow wire, it goes to Right rear bulb
Jumper that to the Dark Blue/orange wire
Go and look if Right rear bulb is on
If not then wire to the rear is bad, this wire does not go thru fuse 7, just FYI

Then jumper Dark Blue/white wire to Dark Blue/orange wire
Go and see if Left rear bulb is on
If not wire to rear is bad

Those are the brake and turn wire/bulbs for the rear

As said, there is a single connector at the rear drivers side that has ALL the taillight wiring

But there are only 4 wires that matter
GROUND wire, for ALL the bulbs
Brown wire for tail lights and license plate lights
Dark Blue/white wire for left turn/brake
Brown/yellow wire for right turn/brake

 

[RazorbackB]

Hey @RonD & @franklin2 - I am just now getting back to this project. My daughter got married, and I have been distracted.

I removed the multi-function switch and tried to jump the wires as you described. I did find the hot wire and was able to make the connections, as you described. It seems everything is working up front with headlights and turn signals, but nothing responds in the rear.

There was one complication, though. The wires don't match the colors described in the schematic or your messages. The dark blue/orange does match and is hot. But I am not finding the brown/yellow or the dark blue/white wire that goes to the rear turn signals.

I am posting a picture of the connections at the multi-function switch. I have to admit that I am about to give up on doing this myself. I may need to take it somewhere to be fixed. Can you help me understand which wires should be going to the rear based on the picture? Otherwise, I am lost.

 

[RonD]

Pink/yellow, grey/red, light blue/orange are for the wipers
Looks to be the "top" row on right connector

Then red/yellow and red/black which is headlight in and low beam out, then a Grey/orange which is high beam out
Dark blue/orange is Flash to pass 12v in

That leaves 4 wires on the other connector, should be 7 wires, which means we are missing some wires
The light blue and white/red is from the Flasher
Green/yellow could be IN from brake light switch, test it
OR out to left front turn and dash

White/blue is right turn out to front and dash

So you are missing 3 wires
Brake in or left turn out
Rear left brake/turn
Rear Right brake/turn

 

[RazorbackB]

Well, that would explain the problem. I checked under the dash and found that it's a short harness that runs from the top of the steering column and connects underneath the dash. All of the wires are present at that location. So, I need to replace the harness. Any help in identifying the correct part is appreciated!

 

[RonD]

Never saw that before so can't help with that

Wrecking yard maybe

Google: 2001 ford ranger multifunction switch wiring harness replacement

Autozone shows some connectors with leads attached

 

[RazorbackB]

@RonD & @franklin2 Thank you for your help. I was able to get all the lights working! I couldn't have done it without your help!