Tail light issues

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JustTodd

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Ok, guys I'm stumped. Got a 73 fj40, driver rear tail light, running light work, hazard light works but no turn or brake light. For the life cannot figure out which wires control these two functions, or what might the issue be.
 
EWheeler

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Ok, guys I'm stumped. Got a 73 fj40, driver rear tail light, running light work, hazard light works but no turn or brake light. For the life cannot figure out which wires control these two functions, or what might the issue be.
Download the electrical schematic, print it out, get a digital multi-meter and troubleshoot.



If you can't help yourself, no one here is going to want to help you. Gotta put in some effort.
 
phroger

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Diagrams help, but the best first step is to check the obvious. Common issues to start with: make sure your lights are grounded. Old contacts, rusty connections can kill the electric vibe. Check the other most likely culprits: fuses, bulbs and cracked / broken connections. Follow the wires from the sockets to the ground to the harness - a hidden slice / crack can wreak havoc. There relays in the engine bay and cabin that drives hazards / turn signals (could be corroded, bad connections). I've had all the same issues you described and each one had a unique flavor of WTH?
 
John McVicker

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I forget on a ‘73…do you have an orange turn signals or no?

If no…sounds like a bulb to me. Check the bulb and also see if you have 12v where you install the bulb. Use a test light…if you don’t have one, go buy one. About $15 & it will be a big help to you.
 
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JustTodd

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I forget on a ‘73…do you have an orange turn signals or no?

If no…sounds like a bulb to me. Check the bulb and also see if you have 12v where you install the bulb. Use a test light…if you don’t have one, go buy one. About $15 & it will be a big help to you.
73 is just a single red assembly, the bulb is good because when I activate the hazards the second element in the bulb illuminates. It's just two wire out of the assembly one for running light, one for stop and turn. I'm having a difficult time identifying the stop and turn wires coming from the other side
 
John McVicker

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Just for fun, switch the bulbs, left to right side etc & see if any change.
 
graham5david

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73 is just a single red assembly, the bulb is good because when I activate the hazards the second element in the bulb illuminates. It's just two wire out of the assembly one for running light, one for stop and turn. I'm having a difficult time identifying the stop and turn wires coming from the other side
Aren't the hazard and turn the same bulb? Or are the hazard, turn and stop all the same bulb. Just wondering if it's in your turn signal switch, but if that was the case the front blinker on same side would be an issue. I don't remember the schematic on those. Does the hazard go through both flashers or just one. Get a test light. Start working back from the lightvand follow the schematic. You will get it sorted out
 
Cromagnon

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Step one: Check all of the grounds on ALL of the lights sockets and housings. If they aren't bright and shiny make them so.
Step two: READ Step one.
Step three: Make sure all of the lights are good and of the right wattage. If you don't know why search on the FAQs. It has been explained ad nauseum.
Step four: Make sure your fuse(s) are good and the fuse holder(s) are bright and shiny. Corrosion is NOT your friend.
Step five: Follow the correct wiring diagram and make sure voltage is where it should be. A continuity light is ok but I prefer a multimeter.
The electrical system suffers from poor grounds everywhere (there is a theme here). You are going to spend some time correcting the issues so be patient.
 
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WarDamnEagle

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On my 83 FJ45 those are separate circuits even though they are the same bulb, etc. My fuse was bad. I would start there especially since that's the easiest thing to change. Even if it looks good change it.
 
awynne56

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Also correct me if I’m wrong maybe the hazard switch has the connections and need to be cleaned. Don’t the blinkers switch and the hazard switch work in combo circuit. I have a 1976 so it could be different
 
YODA 88 62

YODA 88 62

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While your in there add additional grounds to ensure a better ground. While addressing electrical issues with my tail lights, wiggling the light housing would cause random bulbs to illuminate…it’s strange. I riveted a ground wire to the light housing and then cleaned up an existing hole to bolt the other end of the ground on the frame. Then added a little dielectric grease. Lights worked correctly and were much brighter.

49306DCC 6544 4DFC 8014 BBD811AB90F7


6442BD26 473A 403E 94FC 6885DB2FCD73
 
Dizzy

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Also correct me if I’m wrong maybe the hazard switch has the connections and need to be cleaned. Don’t the blinkers switch and the hazard switch work in combo circuit. I have a 1976 so it could be different
Most certainly on a '76, there is one flasher unit, so it is switched. But, the brake lights don't operate, either, and the ground is a common component for both the non-operational brakes, and turn. The hazard switch directs power from the usual 'Turn'-fuse slot/circuit, to the 'Brake'-fuse slot/circuit.
 
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Engineer8000

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73 is an odd year for trying to find an accurate schematic. I have a spare 73 harness (and a 10/72 truck) I can check this afternoon.
 
73FJ40

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The left rear combination lamp in my Jan 73 FJ40 has two wires, green/orange trace for the brake/signal/hazard filament, solid green for the running filament. Note that on occasion, it's a green/black for the b/s/h filament.

You don't mention if the right rear lamp is functioning properly. IF IT IS,

1. Grounds are okay (left hazard wouldn't work without a ground)

2. Brake switch is possibly okay.

3. Could be an issue with the directional switch.

4. Brake circuit fuse is okay.
 
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Engineer8000

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Mine matches @73FJ40. Cycle the turn signal switch a bunch of times to see if that will wipe the contacts and get things working. I am also curious what the passenger side light is doing.

1637779606732
 
Slapshot

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One of the first projects I worked on my truck (a’73) was to take everything off the back and clean it up and re wire it. There was some poorly done trailer wiring that was messing things up.
Also I learned about grounds the hard way. After everything was clean and shiny the lights didn’t work due to bad grounding. Most modern cars have two wires going to a light (power/ground) but Toyota uses a single power wire and grounds to chassis.
4EF835E6 E4D7 4B6A 9170 3141484E6672
3D30119F 88DA 4FD1 A1A6 F40C9252F64A
 
Dizzy

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Also, gotta ask, even though it is late in the game, do the turn signals simply not blink? Or, nothing at all?
 

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