Re-reading this thread, I don’t know if my next 2¢ is what you guys wanna hear, but…

I used 4mm cable-ties (zip-ties), and branched the wires out as they wanted to go.

Separated ‘lighting’ from ‘gauges’ but tied them at the base/common point.
As they were installed, I gave each branch its own tie.

Since the ‘headlamp’ and ‘door ajar’ warning bulbs [1969] are the top-right of the panel, they got their own tie … possibly to “water temp” wiring.

I'll see if I can get pics.

Mine was a ‘rats-nest’ of loose wire, so I’m happy it’s “tidier” … any way you do it, nobody’s gonna see it, but I know it’ll bug you [how I feel, too] if you don’t do the best you can before install.
​​​​​
… also, dealing with original wires right now, not a new harness, so take that into consideration with my suggestion.

 

Check the Assembly Instruction Manual for your 71.
If I remember correctly the AIM for my 73 has some decent drawlings that show how the harnesses run up, under and around the dash and center console.

 

Some progress on my side. Finish line is in sight.
Question for you guys.
Where should the vacuum lines for heater control be routed?

 

I do hope you have an assembly manual for your car.
If not, here are the 9 dash pages from my 72 AIM.
Should be very little difference vs a 71

 

Thank you very much for these pages.
I do have an AIM for 71 but there is no specific page on vacuum routing.
Although I must say that the quality of the pages that you have sent is way better then the ones in 71 AIM.

 

I attended Barrett Jackson for the first time this year. I spotted an 81 that had been mildly customized. What caught mu eye was the nice job that was done on the factory harness on the firewall. Since the factory Plugs are so large I'm sure it was done with a split loom as above. But the ends looked to have heat skink on either end and then some about 1/2 " wide every 6" so along the loom. It really looked great. But what would he of used for what looked like Heat Shrink. In the worst way I wanted to touch around the backside looking for a seem but refrained from doing so. Possibly heat shrink was stretched over the Plugs and then shrunk small enough to grip the loom. Maybe the heat shrink was split, then glued back together. Or they just took the time to un pin the Plugs and then put them back together. Sure looked nice.

 

Your not wrong.
The AIM drawings might as well be cave art.

 

Perhaps these AC vac hose pages will help.

I have seen several AIM manuals, and the reproduction quality is all over the place. Some good, some horrible.

 

Well the radio wiring is done and tested. Works wonderfull!
The issue that I have right now is that none of the center gauge lights work.
Heater light works, radio works, dash works.
Transmission light doesn't work along with all of the center gauge lights.

Are the center gauge lights grounded to the gauges themselves and that is why they don't work?

 

Center gauge lights are the same as the speedo/tach… metal housing is the ground.

Seems like a simple idea, but the devil’s in the details...

All the “gray” wires bulbs are illumination: should be park/head -lights ON. [I literally just put my speedo/tach assy back in.]

The bulbs ground thru the metal frames they’re in, hence the single (gray) wire TO the bulb, and a metal frame to ground.

You need to ground the center gauge console frame.



That’s part of the back-frame of the center gauge console

The other bit is how the back-frame is screwed to the front [gauge hole / face frame], and attached to the [metal] bezel.

That bezel is doing some work for the ground of the bulbs.

Your heater bulb works bc it’s grounded thru [if I’m right, the ‘L’ bracket ground at the lower console / cigarette lighter on the lower console]
AND!!! that wire’s already pinned to water gauge (coolant), radio, tach & speedo:

I know that I know who did the color on this, want to give credit, can’t remember right now - please chime in bc this color diagram is priceless!

Just found it…

robertea did the color, here:

https://www.corvetteforum.com/forums/c3-general/4919427-latest-update-for-1969-wiring-diagram.html#post1609247653

The ‘console ground’ [top of diagram, 2 wires at 1 connector -> cigarette lighter?]

Here?


‘L’ tab / bracket ground-tab : bottom right


Oops, no -> heater lamp 20GY goes grounded to 14B to ‘console ground’ 2x 14B

 

So today I tried to install the center gauge cluster and the moment I attached the fuel gauge wiring the clock and the illumination started to work.
Look like everything is grounded through that and the metal housing.

 

Aha! Success!

Glad to hear it!

You aren’t reading my mind right now are you?
I was just looking at the snip of the wiring diagram I sent [above], and the only ‘chassis ground’ I saw was at the neutral safety switch.

Now, I know you’re concerned about layout, and paying attention to detail, but…

I’d suggest wiring a redundant ground (or two) while you have the dash out.
Just my 2¢

Otherwise… Glad to hear it’s a success!

 

That is exactly what I was thinking, about the extra grounds. Because the moment I took out one of the bulb sockets I blew a 5 Amp small fuze.

 

If it’s worthwhile / if anyone’s interested…
(or maybe just to pat myself on the back)

I'd suspect the majority of issues on or Vettes can be traced to grounds or vacuum. For everything I’ve been through, and everything I’ve put back together (sometimes 2-3 times), I figure if I can get a redundant 14/16/18AWG ground on it, it’ll get one.

The cluster ‘web’ of ground wiring [previous post in this thread] went in to guarantee the Tach and Speedo ground tabs were working together.

I did something similar for the center gauge shell: separate ground wire to the right-side dash frame. [Same place as amp; explained below.]

The Wiper switch has a ring terminal on one side, between the screw and the back of the switch - the switch case is grounded to the console, and (now) to the chassis.

The lil Kenwood amplifier I installed* is grounded to the dash frame AND wired over to the wiper disconnect AND over to the body ground by the headlamp switch (behind the speedo panel, left side). …so is the dash cam & switch for the camera.

I'm sure that’s considered “too much” but I’d rather not have a ground fault wipe cause a component to stop working.

[*Kenwood amp rated at 15A, bench tested at <3A at 75% volume, running a 6-3/4” sub, and a 6-1/2” speaker; Kicker & Kenwood, respectively. Fuses adjusted to: 5A, 2A, 2A, 5A in the fuse block at the amp -> Radio, Camera, Camera, Amp]

What was the line from “Unforgiven”?
’Jesus Clyde … you got 3 guns and one arm!’
’I jus don wanna get kill’t from a lack o shootin back’

 

Primoz,

Let me see if I have good pics of the extra grounds I ran.

Hang on a sec, they’ll be in the next post.

 

Here’s where I [redundant] grounded the center gauge shell:

Ring terminal, 12(?)AWG wire on the bracket at the clock bottom left (in pic), to the right of oil line*

[*oil line heat shrink nonsense removed, elbow re-clocked to ~2:00 since this pic was taken.]

I used the original screws for the housing, and one of the brackets from the original mono-plexer (mono multiplexer ???).

That’s on the back-strap for the RetroManufacturing radio I installed, and the back-strap got heat-shrink’d to save wire chafing. The ground runs to a Packard 56 terminal/connector, and connects to a mating Packing 56 that wires to the camera/amplifier -> dash ground.

Let’s see if I’ve got it…

 

Ok, amplifier assembly aside…

Center gauge ground wired to the dash frame, here:

Upper right, dash frame bolt, the second wire runs to the wiper Packard 56 disconnect which then runs to left front grounding point

LF Ground behind speedo/tach, to the left (in car) of headlamp switch

Pic of the (yes, messy) wiring while I test-fit, assemble, and clean up wiring

 

Installed everything today and all the lights work only the shifter indicator light doens't work.
Where does that get ground from?

 

Hello,
Looking at the AIM, UPC M30, Sheet A4 seems to indicate there is no specific ground connection for shifter indicator light..... so perhaps the ground is through 1 of the 3 fasteners for the retainer item #4.
Look at both the main drawing and the 'A' detail.
Maybe?
Regards.....

 

Coul well be those screws.
Or could it be that it gets the ground once you assemble everything through the heater control mounting?
Heater control is grounded so....