Extra connector after pulling instrument cluster

[ca44]

Hey Guys,
I have a 1983 944 N/A.
I pulled the three instrument cluster and when I went to put it back I realized I have an extra connector. It consists of 2 wires, black which is positive 12V when the ignition switch is turned to on (car not running). The other wire is black and yellow striped. They end in a connector that is round and appears to want to hold a small bulb. All 3 instruments appear to work fine when it put them back, but I'd like to understand where this should go. I have included a photo with the hope that someone can tell me where this should connect to. Thank you in advance to anyone responding.

[M. Murphy]

I have an 83 that I found the same thing in. The connector in my car was not plugged in so on re assembly I just stuffed it back in and didn't worry about it. I think it's for an up shift light in some markets. What were you in there for if I may ask?
I went into mine to replace the instrument illumination bulbs with LEDs. Was only able to replace the tach and speedo bulbs as the combo instrument used a different bulb. Made a huge difference, nowI can actually see the tach and speedo at night!

[NCMT944]

Thank you, thank you! I had the same issue. I removed the gauge cluster and found two wires (one black and the other black/yellow or vice versa). They were fried, apparently due to a short. The insulation was mostly gone and each wire appeared to have a remnant of a brass terminal. My car, also a 1983, does not have an upshift light in the three gauge cluster. Now, I finally know what these errant wires are for, nothing in my case. Finally, I can feel comfortable reinstalling the gauges back into the dashboard.
And, speaking of errant wires. When I was reinstalling the gauges back into the center console after replacing light bulbs there is a bulb holder that I could not find a location to install it. Again, after reading forums I discovered this bulb holder is a holdover from the 928. Once again, not needed in my situation.
I certainly appreciate people taking the time to ask questions and be responded to with knowledgable answers. Thank you.

[originalowner]

It is possible, if you have factory air conditioning, that this is the connection that would have gone to the voltmeter, which is replaced by the a/c control knob. The wiring diagram calls for the yellow/black wire to be grey/blue, but Porsche (actually VW Neckarsulm) may have run out of that color wire for a while back then. Porsche was near bankruptcy then, and could not afford to shut the assembly line down.

If the yellow/black wire varies in voltage with the dash light dimmer, this is very likely the case. All the dimmable bulbs on the schematic are supplied by grey/blue wires.

[Dano944]

Originally Posted by M. Murphy

I have an 83 that I found the same thing in. The connector in my car was not plugged in so on re assembly I just stuffed it back in and didn't worry about it. I think it's for an up shift light in some markets. What were you in there for if I may ask?
I went into mine to replace the instrument illumination bulbs with LEDs. Was only able to replace the tach and speedo bulbs as the combo instrument used a different bulb. Made a huge difference, nowI can actually see the tach and speedo at night!

The lights in the cluster of my ‘83 are very dim too. Are there separate bulbs in every dial? The lack of illumination in my cluster seems evenly low in each dial across tha cluster, so I wondered if maybe there was a resistor that controlled illumination across the cluster. Why would ALL the bulbs be evenly low?

[924RACR]

The original described/pictured wiring sounds like the small bulb and holder that go in the small upper holes of the instrument pod to hold the O2 sensor reset warning light... have stumbled across these on the later 924 2.0L cars...

As for the dash bulb dimmer, that's a rheostat in the headlight switch... but it's common to need to remove and clean the coils of the rheostat. And then replace all the bulbs with hotter, higher-output bulbs, because they're still too dim (though brighter).

Ultimately, the best answer is to swap in LEDs; I have an old old thread on Rennlist about LED bulb fitment, particularly for the early cars. Complete with pics. It's pretty worthwhile, and cheap.