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Offline Mytwojeeps2020

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No power to rear lights
« on: March 05, 2022, 06:25:23 PM »
First, please disregard my similar post of last year.


I find myself again perplexed.  I haven’t driven my CJ5 at night in a long, long time. I’ve discovered that the rear tail lights don’t work when the headlight switch is turned on (pulled out to the second position).

The front and rear parking lights work fine.
The front and rear turn signals work fine.
The brake lights work fine.

If you can read the attached diagram, you will see that I found that the wire going to the rear tail lights has been cut. I've no idea how or why.

The three wires coming from the rear lights connect forward to:
One connects to the left terminal of the light switch,
Two connect to the turn signal switch.

If the cut wire is the culprit, can you tell me where to hook it into the circuit?

Thanks!
First Car at 16: 1958 CJ3B    (RIP)
Second Jeep: 1964 CJ6 (Re-homed in 2022)
Current Jeep: 1961 CJ5 “Olaf”

Offline Rus Curtis

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Re: No power to rear lights
« Reply #1 on: March 05, 2022, 08:09:39 PM »
Edited because I forgot to check to see if text was posted.  Sorry for jumping to conlusions!!

Quote from: Mytwojeeps2020
First, please disregard my similar post of last year.


I find myself again perplexed.  I haven’t driven my CJ5 at night in a long, long time. I’ve discovered that the rear tail lights don’t work when the headlight switch is turned on (pulled out to the second position).

The front and rear parking lights work fine.
The front and rear turn signals work fine.
The brake lights work fine.

If you can read the attached diagram, you will see that I found that the wire going to the rear tail lights has been cut. I've no idea how or why.

The three wires coming from the rear lights connect forward to:
One connects to the left terminal of the light switch,
Two connect to the turn signal switch.

If the cut wire is the culprit, can you tell me where to hook it into the circuit?

Thanks!

Okay, that stumped me for a minute.  I think I understand.  Although an actual question in your text would maybe have clarified this a bit. 

Correct me if I'm wrong.  You're saying that your tail lights don't work when you pull the light switch knob out for headlights, right?


Added:  My bad,  I actually got to read your question but not until after your second post.

That can be corrected.  The parking lights are only on the front.  They are typically yellow and would also function as turn signals - if installed.   The only lights in the rear are tail lights.  They come on with the parking lights so that you have lights on regardless of light switch position, i.e. first notch or second notch. 

Your tail lights in your .pdf attachment show your tail lights connected on the left post with the parking lights.  The parking lights are designed to turn off when the headlights are on.  That's a function of the switch.  First notch, on.  Second notch, off.  Move the tail light wire from that post to the right side, where the wire was cut for the tail lights and your tail lights should work - and stay on with the headlights.

If, for some reason, you wanted the front parking lights to stay on even with the headlights, you could also move that wire over to the tail light post.  Then they would stay on as well.

With the tail light switch hanging from the instrument panel, it will be much easier to move the wires around.  I would also recommend testing (with a meter or a test light) each notch on your switch to confirm which post has power and which doesn't.  Of course, your lights being on and off will tell you too!  Remember that you'll need a temporary ground (a wire with alligator clips is what I use) when the switch is not connected to the instrument panel.

HTH

« Last Edit: March 07, 2022, 04:57:59 PM by Rus Curtis »
'54 CJ-3B "Green Gruntt"
Bantam T3-C

Offline Mytwojeeps2020

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Re: No power to rear lights
« Reply #2 on: March 07, 2022, 03:10:28 PM »
Move the tail light wire from that post to the right side, where the wire was cut for the tail lights and your tail lights should work - and stay on with the headlights.

Rus, I followed your suggestion. When I switched the tail light wire to that right post; when the headlights came on the tail lights came on - but so did the parking lights. However, with that figured out, things finally began to make sense!

Running that tail light wire down, I found that the PO had “T’d” it to the parking lights wire. He set it up so the wire coming off the left post of the light switch powered BOTH the parking lights and the tail lights when the switch was pulled to its first position. Once the headlights were switched on (second position), the tail lights turned off along with the parking lights.

I cut the “T” to sever the wire that connected the parking lights with the tail lights, but left intact the wire from the switch to the parking lights. I then moved the cut tail light wire to the right switch terminal.

Now, the front parking lights (and tail lights) only come on when the light switch is pulled to the first position; when the switch is pulled to the second position, the headlights and tail lights come on, but the parking lights go off, as intended.

Whew, this took a lot to explain, but I hope its clear. The culprit was two-fold: miswiring at the switch and connecting wires that should not have been connected.

Thanks, Rus!
First Car at 16: 1958 CJ3B    (RIP)
Second Jeep: 1964 CJ6 (Re-homed in 2022)
Current Jeep: 1961 CJ5 “Olaf”

Offline Rus Curtis

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Re: No power to rear lights
« Reply #3 on: March 07, 2022, 05:03:09 PM »
Move the tail light wire from that post to the right side, where the wire was cut for the tail lights and your tail lights should work - and stay on with the headlights.

Rus, I followed your suggestion. When I switched the tail light wire to that right post; when the headlights came on the tail lights came on - but so did the parking lights. However, with that figured out, things finally began to make sense!

Running that tail light wire down, I found that the PO had “T’d” it to the parking lights wire. He set it up so the wire coming off the left post of the light switch powered BOTH the parking lights and the tail lights when the switch was pulled to its first position. Once the headlights were switched on (second position), the tail lights turned off along with the parking lights.

I cut the “T” to sever the wire that connected the parking lights with the tail lights, but left intact the wire from the switch to the parking lights. I then moved the cut tail light wire to the right switch terminal.

Now, the front parking lights (and tail lights) only come on when the light switch is pulled to the first position; when the switch is pulled to the second position, the headlights and tail lights come on, but the parking lights go off, as intended.

Whew, this took a lot to explain, but I hope its clear. The culprit was two-fold: miswiring at the switch and connecting wires that should not have been connected.

Thanks, Rus!



Nice work!! 

Quote
...Running that tail light wire down,...

That's what fixed it!  Those Previous Owners..... Bless their hearts.....
'54 CJ-3B "Green Gruntt"
Bantam T3-C