Report on (slow) S2 Coupe rebuild progress

[nthomas1]

I've never heard of that Scott.  I'll certainly consider it.

[nthomas1]

Another phase of cavity waxing today.  Finished off the cross member and handbrake housing.  I've been using the Dinitrol products shown in the second picture.  For out of sight box sections I've first applied the RC900 rust treatment, then 2 weeks later the black 3125 Cavity Wax. I used that approach for the inside lower edges of the doors, sills and main box sections.  For the tops of the front wheel arches at the sides of the engine bay, the rear arch cavity beside the back seat, the front sides of the boot above the wheel arches, and the leading and trailing inside edges of the doors I've used the 1000 wax which is colourless.

I have a couple of electrical questions regarding in-line fuses.  There are 3 of the green in-line ceramic fuse holders in my car: for radiator fan, cigarette lighter and one in the engine bay that I'm not sure the purpose of.  Only one (rad) shows in the wiring diagram. Two of mine are broken and do not fasten properly.  If the green original ones aren't available is there any reason not to use the ones advertised as "Continental" in-line fuse holders?  They hold a ceramic fuse, but employ screw fixing for the wires.

Secondly, does anybody know the purpose of my unidentified engine bay fuse holder, as shown in third picture below?  It was connected via ring terminal to the positive battery terminal.  I've not yet been able to trace the red wire from it which disappears behind the dashboard.  There's nothing shown on my wiring diagram that's connected directly to the battery.  

 

[lancialulu]

re your mystery fuse could be radio or other non factory accessory. You could repurpose it for the fan if it works. Nothing wrong with the continental fuse holders.

[Jaydub]

I think I`m correct in saying that fuse is for the inner Headlamps Norm.

[nthomas1]

I think you’re right John. I’ve just been sent an extract from the 4th edition owner’s manual and that includes reference to the 3 in-line fuses, which my 2nd edition doesn’t. It refers to the fuse “protecting the headlamps”. 

[fay66]

Norman,
I have a new Kenlowe fan switch with a built in warning light.
It's new and yours if any use.
Brian
8227

[lancialulu]

I think I`m correct in saying that fuse is for the inner Headlamps Norm.

these must be the “driving lights” operated separately from a switch on the dash, to conform to UK standards of the day......??

[nthomas1]

Brian - many thanks for the switch offer.   Let me try to use the spare switch that I have in the dashboard now.  If that doesn't work out I'll get back to you.

[nthomas1]

Tim - the issue of the mysterious third in-line fuse is intriguing.   Edition 3 text and wiring diagram show only one fuse (rad), whereas edition 4 refers to three in the text (rad, cigarette lighter and headlamps) but only shows two in the wiring diagram: rad, and cigarette lighter.

Seems strange that the red wire into the third in-line fuse holder comes directly from the battery terminal. 

My inner lights (are they what you would call driving lights?) take their power from the starter motor via a thick yellow cable. I'm thinking this may have been a mod by a former owner, as the fused relay that it employs is a non-standard item.  If that's correct, I expect to find that the red wire to the third in-line fuse is disconnected somewhere.  I'll try to trace it today. 

[eog]

My 1972 Uk spec, RHD S2, has the same green fuse holder to the positive terminal. 
I thought that being a permanent feed, it might be for a radio – not the case.

I have removed the fuse and all equipment seems to work
.
If as suggested it might be for inner lights, why have an un switched feed direct from the battery?
Incidentally my car has a black ceramic fuse for the radiator fan, have not seen a third inline fuse.

[lancialulu]

All wiring diagrams appear to be "continental" format with single filament outer (dipped) and single filament inner (main beam). I think the later UK cars had an H4 outer with both dipped and main in same unit (making the original RHD carello OEM headlamp unit a unicorn). On the later UK cars the inners were operated by a switch on the dash as additional driving lights (useless idea as they blinded on coming traffic before the driver could switch them off). A lot of folk nowadays use an additional relay triggered from the main beam (take you pick where) and switch a (fused) supply through to the inner lights so on main beam all 4 lights come on. This is possibly where your yellow from the starter motor comes from.

[nthomas1]

Hi Tim - my car has the twin filament outers.  That would explain why I have 3 connectors plus earth to each outer bowl, whereas the wiring diagram shows just two plus earth.  I'll look at doing as you've suggested with the inners linked to the outer main beam.

A few things are coming into focus now.  That mysterious green in-line fused red wire from the battery positive terminal is for the inner headlight circuit.  I found it in a later (4th edition owner's manual).   However, It routes to a relay just under the dashboard that isn't shown on that wiring diagram.  I've discovered that the relay is an Inner Beam Main Solenoid as fitted to Series 3 cars.  Maybe that change was a pull ahead on late model S2s like mine, as it looks like original equipment.  Of course it's not in use on my car as it's been superseded by the blade-fused relay I talked about earlier in this thread. Also explains my yellow wire from the starter motor.  That is used in place of the power feed directly from the battery.

[lancialulu]

You have choices. Reinstall the factory lashup or take a feed from the main beam circuit to the new relay....

[Neil]

Wire the inner lamps to be triggered by the main filament on the outer lamps via a relay under the wing and new fused supply from the battery, less clutter on the dash.

[nthomas1]

Tim/Neil - presumably I can just re-purpose the blade-fused relay that I described earlier. At the moment it controls the inner headlights from a switch on the dashboard. It gets its power from a heavy gauge yellow cable from the starter motor, and feeds to a heavy gauge wire running to the inner headlamps.  It has a 20 amp blade fuse.

If I understand you both correctly, I would remove the existing wire that runs to the relay from the dashboard switch (freeing the switch up to be used for some other purpose).  I would replace it with a spur wire from the main beam wire that runs to the outer headlamp (cut the wire and put in 2:1 connector) and connect that spur wire to terminal 86 (input to the relay's solenoid coil).  Surely everything else would stay the same.  When the main beam circuit is activated, the relay will pass through the power from the heavy gauge yellow wire from the starter motor to the heavy gauge wire running to the inner headlights. Does that sound right?