Two Wiring Harness Questions

[jbeach]

Dear wiring harness experts,

I am finishing up the rear wiring harness replacement on my 69 S4 DHC. I have two questions that are probably related.

First, just after the new wiring harness passes from the trunk into the cockpit, two sets of wires emerge from the harness. One set is about a foot long, and the other set is about 4 feet long. Each set is a combination of one, or two solid brown wires, and one purple and white wire. I do not see similar wires emerging from the wiring harness I am replacing. Can you help me identify these wires?

Second, what is the courtesy light? Does the DHC have this, or is this only a light that appears in the FHC?

Many thanks!

-John

[pharriso]

John, you're on the right track, the wires are probably for the FHC's courtesy light, obviously unused in your DHC

[Sploder90]

Think you are right with courtesy light switches. I have a DHC but seems is the same harness.
The wires tuck back from the boot into what would be the pillar area of the coupe behind the carpet trim panel. Must admit I robbed the feed one of these redundant wires on the R/H/S to provide a feed to the electric pump..
you can probably find the other end in a bullet connector at the front

[jbeach]

Thanks, guys. So I assume the courtesy lights are two interior lights mounted inside the top structure, essentially over the outside shoulders of the passenger and driver. The positioning and length of these wires would make sense for those two connections.

I am trying to figure out how to avoid removing my driver's seat and carpet under the driver's door to feed the rear harness forward, but I am afraid that will be required. Do the cluster of bullet terminals at the end of this harness ultimately connect into the interior harness, under the dash?

Best,

-John

[pharriso]

Do the cluster of bullet terminals at the end of this harness ultimately connect into the interior harness, under the dash?

Best,

-John

Yes

[tonyabacus]

John
I am doing the same job right now and can confirm,
1. The wires at the rear as previously stated are for the coupe interior lights
2. I think I read somewhere that there was a courtesy light in the boot on the DHC, perhaps Phil can confirm
3. You may also have a black/white wire in that rear harness (it was fitted in a lot of harnesses) and this is for the
rear heated screen on the FHC
4. Both these sets of wires can be terminated within the harness if not used.
5. Providing all the rear harness colours have not been changed or modified they will show up at the bulkhead
end and link to corresponding colours in the front harness.
6. I would recommend that you change all of the rubber connection blocks for new as they corrode badly inside,
and also clean up each of the rear harness connection pins before joining together, this last job is easier to do
before you thread the cable along the length of the car
7. You don't need to take off the whole of the carpeting along the length of the car to thread the cable through,
loosen around the rear of the door pillar to floor level and again at the front. Then get either an old wire coat
hanger or a length of that flexible curtain wire (the sort that you hang net curtain with) and thread this through
to the front having taped the harness to the end first. This will allow you to pull the harness through with ease.
When you tape the wires to the cable pull make sure the tape covers all the terminals otherwise they stick out
and get caught along the way.
Tony

[pharriso]

John
I am doing the same job right now and can confirm,
......
2. I think I read somewhere that there was a courtesy light in the boot on the DHC, perhaps Phil can confirm
...............
Tony

Certainly NOT on my Jan 72 LHD Federal Sprint, can't say I have heard of one either...

[Sploder90]

No boot light on my 68 S3 SE either.
Although it might be a useful addition given the amount of time I seem to be spending in there recently

[jbeach]

It’s funny you should mention the boot light, as I have decided to re-purpose my long courtesy light wire to power an LED boot light I plan to install. It will be powered at all times, and have a simple on-off switch on the light itself. I’ll post photos when complete.

Tony, thanks for the tips. Particularly the one on how to avoid removing the interior carpeted panel along the bottom of the door. I am finding the front half of that panel to be VERY SECURELY attached, so glad to try the alternative. I am doing that tonight. Fingers crossed...

Cheers,

-John

[Sploder90]

Managed to get to the loom on mine by taking the door seal off and the trim could be eased back

I noted that front to rear loom was attached by plastic ties ( not modern ratchet cable ties) around the interior diamond pattern support structure along the sill which you may need to remove to get your old loom out and I would advise to secure your new loom in a similar fashion to stop chafing.

[tonyabacus]

Phil - One of the problems with old age is that you know you have read or seen something, but its remembering where and when !

John - I forgot to mention that the trim panel is held in place by glue along the top cill edge and by self tapping screws at the front, along the bottom and at the rear. There are some self tapping screws (3-4) along the bottom of the trim panel about half an inch up from the floor, sometimes well hidden, so a magnet helps locate them. There are one/two from memory at the front part way up the panel and also two up the rear wheel arch.

If I remember correctly the front left hand trim panel is made up of two sections split horizontally approximately along the line of the top edge of the cill panel. They are joined together with (3?) small flat plates and then the carpet covers the join. Once you get the edge around the front of the door aperture loose, you can just about get your hand in to feel where the join is and from memory again I think the front self tapper is about two/three inches above that join line.

Sometimes when loosening the trim panel along the cill to thread the harness through, it tears the carpet rather than coming away cleanly, so another tip is to use a hair dryer to soften the glue along the edge of the door seal section you are working on and use a paint scraper between the trim and the fibreglass to part them as you go along.
Tony