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> rear light wiring, trying to sort out. find short to ground?
jfort
post Oct 7 2019, 09:28 AM
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'70 factory six

has anyone made a drawing of the rear light wiring? I have the Zapf schematic but it's hard to read. And the two sides are not symmetric/the same. I may have a short to ground, perhaps it the plastic box bulb holder. I am hoping someone has a diagram of which wire goes to each terminal which connects to each bulb.

in the past, car was hit in right rear. the holder is newer. they may have made a mistake. it all worked until a week ago. now it blows fuses and i have no brake or turn signal lights in rear.

thanks in advance
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dr914@autoatlanta.com
post Oct 7 2019, 09:55 AM
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It is on page 83 of the "tech tips 700" book



QUOTE(jfort @ Oct 7 2019, 08:28 AM) *

'70 factory six

has anyone made a drawing of the rear light wiring? I have the Zapf schematic but it's hard to read. And the two sides are not symmetric/the same. I may have a short to ground, perhaps it the plastic box bulb holder. I am hoping someone has a diagram of which wire goes to each terminal which connects to each bulb.

in the past, car was hit in right rear. the holder is newer. they may have made a mistake. it all worked until a week ago. now it blows fuses and i have no brake or turn signal lights in rear.

thanks in advance

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defianty
post Oct 7 2019, 09:56 AM
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I took these when I dismantled my 73. Hopefully they're of some use.

(IMG:http://www.914world.com/bbs2/uploads_offsite/i.postimg.cc-6621-1570463784.1.jpg)

(IMG:http://www.914world.com/bbs2/uploads_offsite/i.postimg.cc-6621-1570463786.2.jpg)

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defianty
post Oct 7 2019, 09:58 AM
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(IMG:http://www.914world.com/bbs2/uploads_offsite/i.postimg.cc-6621-1570463908.1.jpg)

(IMG:http://www.914world.com/bbs2/uploads_offsite/i.postimg.cc-6621-1570463912.2.jpg)
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rhodyguy
post Oct 7 2019, 10:20 AM
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Are strands exposed on the red and white wires on the center connection?
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ConeDodger
post Oct 7 2019, 10:29 AM
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Bowlsby’s site.
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drem914
post Oct 7 2019, 10:31 AM
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Is this what you meant?
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jcd914
post Oct 7 2019, 12:40 PM
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QUOTE(drem914 @ Oct 7 2019, 09:31 AM) *

Is this what you meant?
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I have a copy of this on my tablet and it has been very helpful as I have redone the wiring to the rear light twice now.

Jim
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jfort
post Oct 7 2019, 02:43 PM
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QUOTE(drem914 @ Oct 7 2019, 08:31 AM) *

Is this what you meant?
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Drem914. That’s it! Perfect. Thanks. My work confirms what you have. I have a shirt to ground in the left brake light bulb housing
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jfort
post Oct 7 2019, 02:59 PM
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QUOTE(jfort @ Oct 7 2019, 12:43 PM) *

QUOTE(drem914 @ Oct 7 2019, 08:31 AM) *

Is this what you meant?
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Drem914. That’s it! Perfect. Thanks. My work confirms what you have. I have a shirt to ground in the left brake light bulb housing


Now I want to add to this the terminal numbers on the bulb housing, for example, RF, 54, 58. 54 is in the middle and connects to the brake light bulb lower filament
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jfort
post Oct 7 2019, 03:30 PM
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QUOTE(jfort @ Oct 7 2019, 12:43 PM) *

QUOTE(drem914 @ Oct 7 2019, 08:31 AM) *

Is this what you meant?
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Drem914. That’s it! Perfect. Thanks. My work confirms what you have. I have a shirt to ground in the left brake light bulb housing


RF 54 58
31 R
58 is running light to dual filament bulb
54 is brake light to dual filament bulb
31 is ground
R is turn signal
RF must be the back up light but doesn’t work on mine

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Rob-O
post Oct 9 2019, 11:42 PM
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I had a similar issue. Cleaned the wiring, cleaned and inspected the bulb holders. When I pulled the reflector I found that one of the wires leading from the bulb holder to the terminals on the INSIDE of the housing was broken and shorting out.
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drifter914
post Oct 10 2019, 09:14 AM
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Sorry George... there is nothing on page 83 of your book " 914 Tech Tips 700" about tail light wiring.
Want to make another guess ?
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dr914@autoatlanta.com
post Oct 10 2019, 11:22 AM
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Sorry you must have the old first publication, here it is on page 83 (maybe time for an updated book?

QUOTE(drifter914 @ Oct 10 2019, 08:14 AM) *

Sorry George... there is nothing on page 83 of your book " 914 Tech Tips 700" about tail light wiring.
Want to make another guess ?

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drifter914
post Oct 10 2019, 01:16 PM
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Sorry too... next time you might want to mention which edition you are referencing.
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jfort
post Oct 14 2019, 03:43 PM
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figured it out. had a short to ground in left tail light assembly. Garold sold me a left and a right in good shape. problem solved. drawing attached

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jfort
post Oct 16 2019, 04:52 PM
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Problem NOT SOLVED after installing 2 newer light assemblies. We checked after installing but they quit on the way home. I suspect a short in the brake circuit. Brake light switch? I don’t even know where it is. Help! Advice?
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Mikey914
post Oct 17 2019, 12:14 AM
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Brake light switch is on the back of the brake pedal on the pedal cluster. switch opens when the brake is depressed turning on the light. Hope that helps


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theer
post Oct 17 2019, 11:29 AM
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That switch can get misaligned when you bleed the brakes. The switch must be engaged to turn the brake light off. A washer on the pedal holds the switch arm in the OFF position. Pushing the brake pedal releases the spring loaded arm which closes the circuit and turns the brake lights on.

If your brake lights are always on, the pedal isn't catching the little arm on the switch (which is what happened to me).
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jfort
post Nov 4 2019, 10:10 AM
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I solved my problem and learned a lot. On the chance it will help someone in the future, I'll relate. Lord knows others' doing the same has helped me immeasurably.

Right turn signal was blowing fuse 9. 4-ways blew 11. This even after I replaced both rear light assemblies. The blk/grn wire to the RR turn signal showed ground. User "Spoke's" diagram helped me realize that the directional lights in the tach are in the same circuit and that's where I found some bad wiring, probably my fault, and a bad ground. Works fine now.

Things I learned: Per Spoke, I confirmed the short was not in the assembly. But I learned that the +12V has a path to ground through the bulb nevertheless and that a simple continuity detector was not good enough. There is 0.8 Ohms resistance to ground through the bulb, but not the 0.0 that would be a true short. So that's when I focused on the tach and found my problem.

Also, I used a newly purchased PowerProbe III. I could do what it did with a DVOM and a 12V source, but the PowerProbe was much easier and faster. But where it said "ground" I confirmed with the DVOM and measure the resistance.

Not often that I figure out a problem, fix it, know how I fixed it and that it is truly fixed. Let me bask in my glory for a day. Something else will come up.

see:

http://www.914world.com/bbs2/index.php?showtopic=341464
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