73 harness routing

[iceman510]

Hey all- I have a 73 sedan that I bought in 100 boxes. I am getting started on reassembly, and the harnesses need some repair and restoration. I'm trying to figure out location as well.

The chassis harness is in the trunk with the most forward mounted point near the fuel filler. I can't remember how it routes to the front. Does it go to the center of the car and then forward up the right side of the tunnel? Do the wires to the dome light go up and over the tunnel to the left side (this part is cut off the chassis harness with the remnants of the dome light wiring coming down the left pillar and ending around the top of the door)?

The drawing in the Haynes manual shows it running along the rocker on RHD vehicle right hand side, so I was thinking maybe it should be the reverse of that for an LHD vehicle, but I kind of remember a car I had years ago that it went up the tunnel side.

Pictures helpful if anyone has some.

Thanks all.

[MikeY]

It runs from the bottom of the gas tank across the rear seat pan. Then around the sguare chanel where the rear seat clips are. 2 of the black plastic clips hold it to that channel while it crosses to the drivers side. You will see 2 small holes in that channel where the clips push into. Then it runs beside the tunnel up to the fire wall and up by the gas pedal and over the e brake mechanism. The dome light runs under the front seat just behind the brace that the seat bolts into. And then up the b pillar.

[MikeY]

Some pictures. I actually ran this harness yesterday. Your timing was perfect. You can see the black clip in one picture and the factory tabs to bend over in a few.

[MikeY]

The over the tunnel wire is for the seatbelt warning system.

[iceman510]

Thanks again. That is very helpful.

I was stumped on the GL/LG wires for the seat belt warning system. They were cut off this harness at the junction by the yellow tape, and on the generic wiring diagram they are not mentioned. I couldn't figure out their purpose until I found a 73 diagram on NICO (of course it is missing the defroster circuits, but that is fairly straightforward).

i did find one picture of the harness winding through the seat area, but yours are much better.

I know in my 71 the harness ran up the right side of the tunnel, but I or the previous owner must have relocated it because racecar.

[iceman510]

If I could prevail upon you for one more photo- of the harness near the fuel tank as it exits the trunk to under the rear seat? The fuel sender wire is also gone, so I am not sure how it locates back there or how long that branch is. Thankfully they kept the defroster wire.

[MikeY]

Here are 3 more. One shows it looped around the brace and held with w factory tabs. The yellow fuel sender wire exits here and goes loose under the gas tank. Then the harness goes up the left had brace. One picture showed the hole that should have a black factory wire holder. They are brittle now and I'm running out. So nothing in the hole.

[iceman510]

Ok, I have almost all the dash harness issues worked out and rewrapped. I will likely do the chassis harness as per the discussion above this coming weekend. I have also started on the engine harness and have a few puzzles. There are two connectors I cannot identify.

This is a 73, so it has some unique items (like the seat belt warning lights, although I may be wrong about that). There are two 4 pin connectors near the voltage regulator connector with the following wire colors:

G G G B- this may be the horn relay connector as I found no other connections for it anywhere else. Most diagrams for other years show three connections, G GY BG for the horn, as does the 73 Mitchell diagram I found. This Mitchell diagram is incomplete for a 73 in other ways so I don't fully trust it. Anyone with a 73 have a horn connection like this or know what it is if not the horn?

4 pin G B.jpg (103.13 KiB) Viewed 1864 times

4 pin G B no 2.jpg (108.5 KiB) Viewed 1864 times

The second connector is the same type, with wire colors Y WL B L

4 pin other.jpg (105.82 KiB) Viewed 1864 times

If you have clues or even pictures of these components, that would be great. I know some vehicles have the emissions retard system with the carb switch, big relay, 3rd gear switch etc., found this on my 71 model harness I have been referencing, but I don't see that relay on the 73 engine harness although some of the other wires near the wiper motor connection appear to be there (most of that was cut off prior to me).

OK, too many questions in one post, I will likely add more yet before I get this all figured out. Any help appreciated.

Thanks.

[MikeY]

The plug near the voltage regulator is for the electric choke on the stock carb. The horn relay is on the same shock tower by the fusebox. It's got the 3 spade connections not a plug.

[iceman510]

Thanks Mike, big help. I have not had a car with the electric choke before, and I have not seen it on any wiring diagrams. With that info I could google and found posts on here and Ratsun talking about it. Wires colors and locations make sense.

I did find the three individual horn relay connections. Not sure why I missed them before.

Now, what is the relay connector with 3 green and one black wire? Still hunting for that, but I have yet to trace the actual wire routes in the harness. Been working on removing unneeded stuff and getting ready to re-wrap the harness.

[iceman510]

Alright, back for more!

I finally have the interior done, dashboard structure and steering column painted. Ready to put the heater etc. back in, so time to install the dashboard wiring harness. Since it was never in the car I have a few things to ask about.

Where it runs through the center, is one part of it hooked in the clips at the top (bottom side) of the dash?
Does this continue on the right hand side, with one branch that heads to the engine room harness in the upper clips (on the dash structure) and one in the lower clips (on the firewall)/
Where does the defrost relay mount?
Do the branches for the turn signal and hazards go through the hole in the upper center of the steering column mounting bracket?

If anyone has pictures, that would be great. Or I can take some and you can point out my errors.

Thanks.

[yenpit]

Yes, on all accounts of routing the harness..........I JUST pulled a 1973 dash apart last week! There are two big flat steel "clips" welded to the steel dash frame at various points, they are plasti dipped to protect the harness & basically wrap around the harness to hold in place. The harness weaves thru various holes side to side.

If the defrost relay is a larger yellow zinc plated metal relay, kinda in the middle of the harness, it mounts to the lower edge of the dash, kinda in front of & above the heater box. Mount it with the body of the relay UP, so it's not hanging down in the visual!

The turnsignal/hazard sub harnesses come in to the plastic steering column shroud right around the ignition lock assembly & snakes in at the center. The harnesses do NOT route on top of the steering column, they do NOT pass thru that kinda half round plastic cap. That plastic cap was an aftertought to close up that half round hole, when the USA spec locking steering column was installed!

Hope that helps!

TJ

[iceman510]

Alright, a few more. Hopefully TJ has recent experience again.

Where exactly do the two flashers and also the light bulb holder for the two lighted switches to. I thought I figured out the flashers, but not sure. Do they go on the side of the column mount/pedal box?

I think I can put the switch light holder in the lower channel of the dash frame right below the switches and the air vent. I got rid of the a couple of the seatbelt warning system items, so I have a few extra plugs to tape off, including the clutch switch for the timing retard.

Thanks again. This is more complicated than I expected since I have never owned this car when it was together.

[yenpit]

Alright, a few more. Hopefully TJ has recent experience again.

Where exactly do the two flashers and also the light bulb holder for the two lighted switches to. I thought I figured out the flashers, but not sure. Do they go on the side of the column mount/pedal box?

I think I can put the switch light holder in the lower channel of the dash frame right below the switches and the air vent. I got rid of the a couple of the seatbelt warning system items, so I have a few extra plugs to tape off, including the clutch switch for the timing retard.

Thanks again. This is more complicated than I expected since I have never owned this car when it was together.

I replace both turnsignal & hazard flashers in EVERY CAR with an AutoZone Novita brand heavy duty ELECTRONIC flasher part #EL12 (same for both). They do not come with a mounting tab, so I simply zip tie them to the main harness, so they aren't just hanging there. But yes, the OE flashers mount to the side of the pedal box with a self tapping phillips head screw. The illuminated switch fiber optic canister/bulb holder can really be mounted anywhere, but unless you are lengthening the plug harness, it just needs to mount near the plug at the main harness AND close enough for the fiber optic cord to reach the switches

[iceman510]

Alright, I have most of the dashboard and instrument cluster area handled. Some more questions on the defroster.

I need to know what the power connection to the defroster looks like. If I am reading the wiring diagram, there is an inline fuse. i have the blue wire located, but nothing after that. Will any inline fuse work? Rating? 15 or 20A?

Secondly, is the ground side of the rear window defroster just a pigtail that grounds to the body? I don't have anything there. Picture would be great for the location of the attachment point to the body.

Thanks.