What's this wiring for ?

[EuropaTC]

Hi folks,

Despite having owned this car for well over 35yrs, pulled it apart on several occasions (sometimes not always planned) and generally messed about with it, I'm struggling at the moment with a couple of mystery wires in the doors.

Now I'll admit that I rarely pay attention to doors as long as they don't leak but earlier this week I decided to fit relays to the window motors, together with a heavier gauge power feed/earth return to see if I could get them operating a bit better. And also remove the load from the switches when movement starts or when you hit the stops and the ammeter flicks up.

It was all going to plan until I try to feed in the new power/earth wiring and it won't fit through the tube, the existing loom is taking up all the space. So I looked at what's there and I have;

1. Thin speaker wiring - something I put in with door speakers in the 80s.
2. OEM Black/Blue & Brown/Yellow wiring for up/down from the switch.
3. OEM black earth lead.
4. And two wires,  Red & Black with bullet terminals in their own sleeve, all wrapped inside the loom tape. Far too heavy gauge for speakers, they look like something you'd use to power the motor itself.

The mystery leads are just hanging free, coiled up where they enter the door and out of sight. Now I've probably coiled them up in the distant past when I've had the doors off the car but for the life of me I can't remember (or ever knew ?) what these wires were for. 

My initial guess was lamps fitted to the rear of the doors but having looked at the S2 Fed/TCS Fed & UK wiring diagrams I can't see anything. Because they're not doing anything and the car still runs I'm going to pull them and use the space for my heavy gauge power/earth wires but now I'm puzzled about why they were there.

Anyone have an idea ? is it something fitted to anyone else's car ? It seems very unlike Colin Chapman to add extra cost where it's not used, to say nothing of the extra weight in taking the wires for a ride ?

Brian
 

[S2Zetec54]

…..difficult one

As you say lighting at the end of the door for a overseas spec or…….some sort of central locking idea?

[4129R]

IMHO, the only way you will find out what the wires are supposed to do is to find the other end of the red wire.

My guess is if it is just a red wire, with no trace colour, it has something to do with the side light wiring, and in my experience of fitting 5 new looms, the only completely red wires are the side light wires, which are connected to the dash light switch, and the fuse box.

[Bryan Boyle]

Hi folks,

Despite having owned this car for well over 35yrs, pulled it apart on several occasions (sometimes not always planned) and generally messed about with it, I'm struggling at the moment with a couple of mystery wires in the doors.

Now I'll admit that I rarely pay attention to doors as long as they don't leak but earlier this week I decided to fit relays to the window motors, together with a heavier gauge power feed/earth return to see if I could get them operating a bit better. And also remove the load from the switches when movement starts or when you hit the stops and the ammeter flicks up.

It was all going to plan until I try to feed in the new power/earth wiring and it won't fit through the tube, the existing loom is taking up all the space. So I looked at what's there and I have;

1. Thin speaker wiring - something I put in with door speakers in the 80s.
2. OEM Black/Blue & Brown/Yellow wiring for up/down from the switch.
3. OEM black earth lead.
4. And two wires,  Red & Black with bullet terminals in their own sleeve, all wrapped inside the loom tape. Far too heavy gauge for speakers, they look like something you'd use to power the motor itself.

The mystery leads are just hanging free, coiled up where they enter the door and out of sight. Now I've probably coiled them up in the distant past when I've had the doors off the car but for the life of me I can't remember (or ever knew ?) what these wires were for. 

My initial guess was lamps fitted to the rear of the doors but having looked at the S2 Fed/TCS Fed & UK wiring diagrams I can't see anything. Because they're not doing anything and the car still runs I'm going to pull them and use the space for my heavy gauge power/earth wires but now I'm puzzled about why they were there.

Anyone have an idea ? is it something fitted to anyone else's car ? It seems very unlike Colin Chapman to add extra cost where it's not used, to say nothing of the extra weight in taking the wires for a ride ?

Brian
 

In my S2 (realize that it MAY be different), it was a pair of wires that went to a gang connector right in back of where the radio was located.  Assuming for the door speakers (you said you added your own speaker wires?); back when the cars were built, stereo car radios were a rarity but two speakers would not have been rare being driven off a mono feed...I'd look for a couple lucar multi-female gang connectors (one with all black plugged in, the other with all red plugged in) up in the harness in the middle of the dash...ring out with a VOM, betcha that's your answer. 

Just a thought.

[Kendo]

In that general area, the door-open switches use bullet connectors. Could those have been disconnected and bundled with the wires that should go through the tube?

[TurboFource]

This is what is on TCST......no red wires

[Kendo]

For those interested in a subtle mod, I made new tubes with 3/4” pipe; 50% larger diameter gives 100% more cross section for wires (more or less). It’s pretty easy to braze brass, and the geometry lets you use the original rivet holes.

[EuropaTC]

Hi folks,

Thanks for all the replies and suggestions, it's going to sound strange but I'm almost pleased not to have a "oh they're for xxxxx, didn't you know ?" 

Alex, the couple does look like sidelight circuit wiring but why they go into the door I've no idea. Anyway, they don't go there any more, they're coiled up inside the cabin and when the temperature increases above zero then I'll follow Bryan's suggestion to see where they end up. They just look too heavy for speakers and all the those I've had use spade terminals not bullets.

But we'll see. I don't like loose wires hanging around so when I find the ends I'll post where they came from. Place your bets gentlemen......

As an aside, this morning I got the first side wired up with relays in place and wow, what a difference.  Previously without the engine running/charging, both windows would arthritically crawl up or down and only showing some enthusiasm when the alternator kicked in a few more volts.

This afternoon, still at -2C outside and not much warmer inside (so the battery voltage would be down), with 30amp cable for power/earth and relays the window was moving faster than they did with the engine/alternator contribution. I didn't bother starting her up to see the final result but heck, it's almost like a proper car now.....   

Brian

[4129R]

See if the red wire has any power when the side lights are on.

If not, tracing the other end of the wire will be a challenge.

There is a light by the choke and heater controls on the centre console which comes on with the sidelights.

[SilverBeast]

There is a light by the choke and heater controls on the centre console which comes on with the sidelights.

I thought that was just on the Federals

[4129R]

I thought that was just on the Federals

Some cars got fitted with strange components, whatever they had if they had run out of what should be fitted. 

My first TCS 75032429P the 6th last made, had a Federal bodyshell, as presumably that is all they had left.

[Pfreen]

I have not seen a schematic where the choke/heater light comes on with the door switches.  The door switches only control the light attached to the firewall.
I believe the red and black wires you found are not stock and were added by a previous owner, perhaps to do what you plan and add relays.  Since they are there, I would trace them out and use them.  I installed relays for the windows, and it works well by increasing the window speed and saving the switches.

Btw, I have never seen stock lights installed in the doors.  They are not shown on any schematics I have found.

[FourLoti]

Hi: Reviving this thread from late last year. I was just about to post the same question.

Sounds as if they are superfluous, but good to know I'm not alone!

Ron

[4129R]

Radio loud speaker in the hole in the fibreglass door. It should have the other end where the rectangular cut out is in the centre of the dashboard.