Wiring Green Face Gauges: What goes where with pictures...

[19-911-65]

Its time to install the gauges on my son's '65 and we can't quite make out all the wiring connections. Looking to complete the wiring connections and leave a trail so the next person will have a concise and detailed explanation/pictures to go by.

So if you will...copy and paste, then fill in the blanks with what wire (color code) goes where...with any other information you may have to help the next guy.

Many thanks,

Glenn

Oil Level/Fuel Gauge:
1-
2-
3-
4-
5-
6-
7-
8-
9-

Oil Pressure/Oil Temp
1-
2-
3-
4-
5-
6-
7-
8-
9-
10-
11-

Tachometer:
1-
2-
3-
4-
5-
6-
7-
8-
9-
10-
11-

Speedometer:
1-
2-
3-
4-

Clock:
1-
2-
3- (#3 needs to be at about the 5 o'clock position)

[19-911-65]

Picture of each gauge:

[304065]

Please spend some time with L57, the wiring diagram, which will get you 90% of the way there. I say this because it will be a lot faster and more reliable than trusting this to the collective group. If you have specific questions, no problem.

[beh911]

L57 can be found here:
http://members.rennlist.org/911pcars/WiringDiag.htm

[19-911-65]

L57 can be found here:
http://members.rennlist.org/911pcars/WiringDiag.htm

Thank you...that was helpful!

[304065]

Glenn,

The diagrams are the second stage of complexity for Porsche-- they got one step more complicated than the VW/356 type with the LWB diagrams, then Porsche threw in the towel and went to current flow diagrams, which help you diagnose problems, but don't really look like a car!

Anyway let's get started, now that you have spent the requisite time "apprenticed" to L57!

The easiest way to understand the gauges is to not go point-by point but think in terms of subsystems.

The wires break down into groups like:

+12V power, which is the blue wire with yellow stripe, that connects to "15" on the gauges. "15" is DIN 72552 for "battery + from ignition switch" and in fact if you trace it back, that's where it goes, to the unfused side of fuse #1 and thence to the light switch and then back to the ignition.

Ground, which 99% of the time in a German car is brown. Since the instrument cases are in contact with the body sheetmetal you might assume that ground is the bare metal tabs on the back of the cases, and this is so.

Instrument lighting. This is a thin black wire with a blue stripe. Do you see how every gauge has it, and the blue/black daisy-chains across the gauges, and is shown connected to a circle with an "X" inside? Those are the symbols for the bulbs.

* * * Safety tip * * *

The black/blue is unfused and the insulation was made on a Friday after lunch. Look VERY closely at your harness, it's actually a separate, detachable, very fine almost 20AWG harness with some rubber tubing protecting the various "wye" connections where it splits. There is a male faston covered with a molded rubber tab at one end. It is VERY important that no copper strands be protruding from the rubber-- it will short to the gauges or to the body sheetmetal and the party will be ON! (The party in which one fabricates a new harness while friends look on in disbelief!) It is a great idea to get one of those bakelite fuse holders and wire it in-line, a period look and good protection for this known failure spot.

* * * End Safety tip * * *

And then of course you have the signal inputs for the various senders. Simple enough.

. . . and then the Factory throws a curveball, because the left two gauges (fuel/oil quantity and oil temperature/pressure) are reversed left to right! Warren used to say that the most junior engineers got tasked with making the wiring diagrams, and there's a lot of wisdom in this! (As opposed to the engineers that designed them!)

Now we can go one at a time. Left most gauge in your first photo is upside down, the gauge illumination connects to the bulb holder, which goes at the bottom! That is a black/blue, wire 4 in your diagram. There is a separate brown ground harness, goes on the metal tab 3. The ring terminal on that harness goes on the ground stud down where the cannon plugs go through the body.

Next is your terminal 2 which has a "G" next to it, is that for "G"round? "G"angsta? No in fact it's most probably the German word "G"eber which means "sensor" or maybe "G"erät for "apparatus." In any event it's not the ground! So we connect the sender for the oil level, a green/white wire.

Last on that side is 1, which says "+" which we now know is the blue/yellow switched power from ignition. So the blue/yellow from the harness goes there. This harness is built into the main harness and is also a daisy chain, so you hook up each successive female faston as you go across.

Next: fuel gauge. We'll follow your numbering convention here:

5 +12V blue/yellow (actually the second on the chain, first goes to +12V on the oil side)
6 Geber, a green wire to the fuel level sender for the level
7/8 this is +12V blue/yellow on one terminal of the bulb holder, then black from the fuel warning light contacts on the other
9 brown ground (but you knew that!)

Whew! That is one gauge!

[19-911-65]

Please spend some time with L57, the wiring diagram, which will get you 90% of the way there. I say this because it will be a lot faster and more reliable than trusting this to the collective group. If you have specific questions, no problem.

Good idea and I have done that, and you are spot on with the 90% part. The wiring diagrams, when it comes to the lights, are all but unreadable/understandable for me. Most of my issues are with the brown jumper, the yellow w/blue jumper and a specific question with the oil tank sender wire (green w/white). The oil tank sender terminates in the front trunk just outboard of the fuse panel (both on the original harness and a '67 912 harness I have). Question: is there a relay or other devise that makes the connection to the gauge or is the connection just made up "wire to wire" in the front trunk to the gauge?

Also it was my desire to have an easy to ready diagram here onsite to help with future owners. I have never seen a bullet proof wiring diagram for a '65.

Glenn