Back up light circuit question - 82 911SC

[trojwl]

Can anyone tell me the location of the connector in the circuit where the gray wire from the switch in tranny turns to gray/brown (to lights).

I believe it may be causing an issue.

I'm guessing somewhere in the engine compartment.

Also, on wiring diagram, what does "NCA" stand for? It is printed where wire color usually is.

Thanks

[Bob Kontak]

Timing is everything. I am wrestling with the back up lights on my 81. My trans switch is grounding.

Anyhoo - You ain't reading the right diagram, Broseph. In this website we have the 1982 diagram. The color changes at the 14 pin connector way in the driver's rear of the car. Pin number six. Get your reading glasses on and check it out.

I can help you out plenty if need be. Check the tech info center for the diagram. Here is the picture:

[trojwl]

Let me run this past you.

I get 11.65 vdc on green wire (when disconnected from switch). I should be able to merely short the connector wires (simulating trans in reverse) and get the lights. This is not happening.

Usually, from my experience this is a bad connection. When you put the load of the bulbs into circuit, resistance usually kills you.

I've checked connections around fuse terminal (#11). They look fine. The only other connection is the connector where color change occurs.

The good thing about all this is that it does not keep me off the road. I just need to keep aware when backing up.

thanks,
Warren

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[Bob Kontak]

Originally Posted by trojwl

I get 11.65 vdc on green wire (when disconnected from switch).

I don't like that number.

Yes you can join the front to the back and simulate. In fact, I am "going under" tonight and will provide my number from the green wire. Also, will marry the lines and see if the bulbs light up and report back.

Does the 2000 have Bosch MFI?

[donagain1]

Have you found the 14-pin connector yet. the one that pins 5 & 6 have the green/yellow on both sides of pin 5 and the green to green/brown on opposite sides of pin 6?

May we presume that you started your troubleshooting at either tail light assembly, inspected the bulb(s), determined that there is a good ground present on the brown wire that jumpers over to the turn signal section of the assembly, and no presence of 12V on the green/brown lead at the socket terminal when the Xmssion is in Reverse?

You indicated that you detected 12V on the green lead with it disconnected from the Xmission switch, but per the diagram that is not possible unless you are somehow mistaking the green/yellow for the solid green. The only place that the solid green wire exists is in the harness between the switch itself and the 14-pin connector.

I'm going to go see Jack Daniels now, me old eyes are hurting.

[donagain1]

Forget what I wrote before regarding colors... I shoulda started drinking earlier. You SHOULD be getting 12V on the Green/Yellow with it disco'd from switch, and also on the solid gray on pin 6 of the 14 pin connector with key on and Xmission in reverse, as well as on pin 5 (gray/brown) of either of the 6-pin connectors that are at the tail light assemblies.

[trojwl]

This light failure happened last week after i got it homefrom the shop. I had tranny swapped out. I can't see what he could have done to cause this. So I figured he didn't plug a connecotr properly.
I'll resume troublehsooting tomorrow.

[trojwl]

I discovered that someone had spliced on the last foot of the cable to switch. after undiong splice, I can see the wires are indeed green/yellow and gray/brown.

Also, I have this portable power supply for jumping cars. Basically a 12 vdc power supply. I can put this battery on gray/brown wire, ground battery to the chassis and the back-up lites turn on.

Tells me that the problem is "upstream" on green/yellow circuit leg between switch and fusebox.

Since it is nothing more than a single wire going to fusebox, I probably need to readdress the fuse box. I may get lucky and find kinked wired or something similar.

Worse case is replacing wire.

Will keep you apprised of progress.

Warren

[donagain1]

Warren, forgive me for covetting your lift ramps. Beautiful car too~
If that green/yellow has no 12V standing on it at the switch, then it's a sure bet that the 14-pin plug is not well connected, or the fuse is not making good contact. The diagram for the '82 is drawn as a "functional schematic", and doesn't show whatever else connects through the 14-pin thingy. It may be a plug at the end of a rather stout harness, with other equipment's wiring passing through it, or it might simply have only the leads for the backup lights through it, and thus be at the end of a thinner harness. My wild guess is that it is situated in the driver's side, and can be traced via the switch harness that you already found.
Don

[trojwl]

Not only ramps but also hydraulic lift also in other bay.

Best investments I've ever made.

[trojwl]

According to your drawing the two-conductor cable going to switch also goes through same 14-pin connector as does the wire to the lights.

I'm hoping I don't have to fool around with that connector.

Tomorrow I'll get my DVM adn wring out the green/yellow wire from fuse to switch connector.

Could be a short or bad connection. It should be fun trying to find the culprit.

[trojwl]

It's midnight and I couldn't stop thinking about connector so I'm in garage searching engine bay.

Can't find it.

Any clues??

[Joe Bob]

My LED back up light conversion......

[donagain1]

Okay, now you're just hurtin' me Warren. S-weet!

I'll slither under my 85 in the morning and see what I can see... shouldn't be too different. I'm thinking that following the two conductor harness back from the left rear tail light's six-pin connector should lead right to it. You may have found it on yours by then.

JB, at first I thought the pic was of a Redondo Beach cop car on Sepulveda taken through your rear view mirror.

[Bob Kontak]

The 14 pin connector is attached to the relay panel behind the plastic cover held on by wing nuts. It is easy to get to and I think that may be a potential culprit.

Upstream - wire starts at fuse 16 - travels through the 14 pin connector at pin five to the trans switch.

Downstream - Back to 14 pin connector through pin 6. Then travels to the "through the inner fender" passenger side round six pin connector (Pin 5) in the far back corner. A jumper wire travels from the passenger side corner to the drivers side round six pin connector (Pin 5)

That is the layout. I checked my green wire last night and it had 12.3 and battery had 12.4. Your 11.65 shows resistance if your battery is above 12v.

Also the 12 pin connector may have been pulled or stressed when trans was pulled out (assuming engine came out with it.) You need to find it and check the physical connectors in there - they can easily be dislocated from their sockets inside the connector.

Long story short - I am with donigan1 regarding suspect connector.

[Joe Bob]

The red and blue is the car stereo.....the white lights are LEDs on each side of the license plate.

Thought it was a neat effect.

Anyways, since I had converted to "R" tail lenses I needed to fab back up lights. I used the stash of LEDs I had laying around from the key fob conversions....

[pete3799]

By the way NCA stands for no color assigned.

[Bob Kontak]

Originally Posted by pete3799

By the way NCA stands for no color assigned.

Good input. Is that from Bentley? I don;t remember seeing that term in the factory diagrams.

[donagain1]

Bob, aren't the factory manuals printed in German? I know that the one that's in the Haynes for an '85 has abbreviations like "ws" for weiss or white, "rt" for röt or red, and "s" for schwarz, like our former governor out here. Also, Bob, did you mean to type above that the 12V comes via fuse #11, rather than 16?

Warren, it sounds like you should be able to get it soo, let us know.

JB, key fob led? Very interesting! Any pic or key opened up that you can PM?

[Joe Bob]

Rennbay.com :

Be advised the guy got the polarity swapped. LEDs are directional.....

I have bulbs if you need them.