Left Rear Tail Light Low voltage

[Brand138]

Hello Patrol world!

I am coming in hopes someone could help shine some light on why my left rear light is getting about half the voltage it should, so around 5 to 6v. I have tried tracing the wires, checking the ground and nothing seems to work. I checked voltage at the turn signal switch, the fuse box, the light itself, all read the 5 to 6V. I know nothing of electrical and before I take it to a mechanic I thought Id ask if anyone has any thoughts on the matter!

I ran power to the left socket from the right and it works so it's not the socket or light itself.

Thank you all for your help over the years! Otherwise she is running great

[Esteban]

Most probably the culprit is the turn signal switch.

Tomorrow I will have access to the electrical diagram and be able to elaborate a little bit into this.

[Esteban]

I read again your notes and realized you are getting 5 to 6v in many places (turn signal, fuse box and left light socket) so what I mentioned yesterday is probably not the cause. The voltage at the fuse box probably points to a bad contact there, either by the main feed from the battery or just under the fuse for the turn signal. In this case, the fuse is the one for the Stop Lamp, as per the following table:

Position ... Capacity ... Circuit
F .......... 10 A .......... Flasher
W ......... 10A .......... Wiper motor
R .......... 10A .......... Reverse lamp
S .......... 10 A .......... Stop Lamp
L .......... 20A .......... Lamps, Instrument, Head, Tail, Park
H ......... 20A .......... Horn

Are you getting 5 to 6v in all other contacts of the fuse box?

[Brand138]

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Thank you for your help Esteban! You have helped me so much over the years both directly and through others posts so I thank you very much!

I don't think I ever showed a picture of the patrol since I've restored it (at least as far as it is now) so attaching an updated pic of where your and other people on this site have helped get it to!

I am testing the fuses now, I cleaned the contacts about 2 years ago but see they have become quite dirty once more so I will clean them all up and test that first. I'll let you know soon!

[Esteban]

Looks beautiful! Congratulations!

[Brand138]

Thank you! It's been a lot of fun!

As for the rear light, I cleaned the contacts well and checked fuses - still no luck sadly.
Any other places you recommend I should look?

[Esteban]

Thank you! It's been a lot of fun!

As for the rear light, I cleaned the contacts well and checked fuses - still no luck sadly.
Any other places you recommend I should look?

Probably you have to start looking for voltages at different places to try to pinpoint where you have the drop.

• Voltage at the battery

• Voltage at alternator and ground

• Voltages at both sides of the fuse box terminals and ground

• Voltage at rear lights

Hope somebody else chimes in with some ideas.