US spec. tail lights converted to UK MOT compliant.

[Kneeslider]

A small but rewarding sub project has recently been converting my 356SC tail lights from their original US specification, where the all red lens contains a pair of single filament bulbs, one of which is the low wattage tail light, nearest the centre of the car, and the other is the higher wattage bulb, to the outside which acts as both the indicator and the brake light.

I'm not sure what others have done, but, in my case, I procured a pair of red and amber lenses, and fitted those, then realised that I would have amber brake lights, which is clearly unacceptable! So, a little ingenuity is going to be required.

First of all, I bought a pair of these from Ebay, for £4 or so each, along with a pair of twin filament bulbs.



Then, on examining the Porsche teardrop shaped lamp assembly, realised that the pressed in bulb holding insert could be removed by using a Dremel to take off the solder at the base, that holds the inner to the outer sleeves of the tail light, and prize away the swaged part.



On dismantling the plastic sleeve from the new twin filament bulb holder, it appears that the new part fits very snugly inside the shell, where I had just removed the old bulb holder.



Because the new bulb is rather larger than the old one, it needs to be a little lower in the light unit. So, I fitted the new bulb, and lens, to make sure that there was enough clearance, and the new lens didn't foul the bulb.



All I thought that it would be wise to solder the new inner to the old outer holder, and ran a separate earth lead to pick up onto the bodywork.

All that remains now is to disconnect the brake light switch from the indicators, and run a separate wire from there to the rear of the car and to the new bulbs.

[barryb]

Hi Kneeslider

I think you will find a wire already in the loom to connect your brake lights up.

Barry

[Havana Henry]

Funny you say that Barry, I was under that impression, but a very close look (also by my more electrical savvy friend) did not show up said wire when I did the same job recently.

As I had to change all the gear linkage bushes anyway, it wasn't too hard to run an extra wire from the master cylinder neatly through the tunnel to join the other wires out the back.

Hopefully your extra loom wire will be present Kneeslider....

[Kneeslider]

All good info chaps...

However, does anyone have any idea of the colour of the mythical extra wire, and where it emerges from the front of the car. Under the tank perhaps?

On a related subject, I have quite a few odd wires under the dash that I have been trying to sort out. Both the wiring diagrams I have are just about unusable, because they are so small, and its impossible to identify wire colours on them.

Does anyone have any better ones?

Good to hear that your resto is progressing James. Still on target for CLM?

[barryb]

Hi Kneeslider

It's been a while but as I remember it terminates at the rear right by the tail light and into one of the plugs at the front of the car. I seem to remember locating the wire at the rear and checking the colour then checking for an unterminated wire in one of the sockets at the front near the brake switch, then checking with a continuity tester to make sure. Then its as imple conection from the brake light switch to the connector and a wire to each of the stop lights.
Sorry I can't be of more help,

Barry

[KS]

Question: due to the age of the vehicle, do you actually need to do this? Certainly neither my 1965 Beetle or 1966 912 ever needed to have red turn signals, and one of my other older Beetles had US-style flashing brake lights for turn signals, which was legal.

[Havana Henry]

I think so Keith, but not 100%. But aren't orange indicators a legal requirement these days? I also thought MOT testers took a dim view of flashing brakes too.

To be honest I thought briefly about these things recently with mine, and decided to make it UK spec anyway. It was more a concern of other drivers not understanding my lights (all red blinking lights- what's that mean?!) and rear ending me rather than the MOT man.

Speaking of which, MOT'd last week Jon, so CLM is all go.

[Kneeslider]

Speaking of which, MOT'd last week Jon, so CLM is all go.

Yay! Its great to get a project on the road and legal! Well done!

I'm with James on this one Keith. It might be legal to have US spec lighting, but I guess that the lights aren't really there for your benefit as the driver, but the benefit of others, and signalling your intentions to them. It's just what people expect, and I think its best not to give them an excuse to misinterpret your intent.

[pauldvern]

The cable I used for the brakes on my A was the extra line for the Carrera fuel pump which went from under the dash to the rear, but we couldn't find this on James's car.


Paul

[Jonny Hart]

Flashing red rear indicators aren't just confined to US cars. Some British cars had these until the early sixties. Had them on a '63 Moggy 1000 (along with flashing white fronts combined with sidelights). Used to pass the MOT fine but usually with a bit of explanation!

Nice job on the upgrade though!

[Kneeslider]

OK. Today, I'm going to pull out the wiring at the back of the car in search of the elusive spare wire. I have found an online wiring diagram for the 356 C on the Registry website which shows this wire, and explains the proliferation of earths I have discovered which originate from the left side rear light unit, and earth the number plate lights and reversing light.

I have no idea why it was designed that way. Perhaps the guy installing the loom was paid by length of wire installed?

Anyway, this spare wire appears to end in a five way terminal block. Anyone know where I might find this? Under the dash, in the luggage compartment? A quick look see last night when I got back from work didn't turn anything up.

[roy mawbey]

Nice neat job!! Around 40 years ago I did the same on my 'A' At that time even PCGB advised the modification would be necessary to do. So I have on my car the twin pole bulb holders from a 1950's Ford consul. These soldered into place and I ran the separate wire from the master cylinder through the tunnel and neatly to the back. At the time I looked for a spare wire never found one interesting that Paul did, inserted by the factory for the Carrera fuel pump.

As Keith mentioned he is correct if the car was supplied and accepted at the time with a particular standard of lighting it could continue that way. A guy I know had an American car that had all red lighting and they passed it. But... tell me would you feel happy with orange stop lamps working in conjunction with flashers on a 6 volt system when you have some hooray Henry up your back side at 70 mph on busy motorway

Sensible job well done!

Roy

[pauldvern]

I had the advantage of my loom being out of the car when I was sussing out the wiring, a lot easier!


Paul

[Kneeslider]

Some progress today. I can confirm that the phabled spare wire does indeed exist!

But you have to disconnect all the wires from the lights, reversing light, and number plate lights, grub about under the car to unhook the wires from the tangs on the body, then pull it all through the hole for the passenger's (LHD) side.



You can see the mythical wire taped to the loom, with its own bullet connector, dipped in wax.

So, after doubling up the missing cable, and running it to the brake lights I found the five way terminal block under the dash where other end of the spare cable has been biding its time, to come in useful after almost 50 years.

The feed for the brake switch comes from #1 fuse, then through the switch, then back into the indicator switch unit. It's a simple matter to remove the wire from the indicator switch unit, and connect it to the spare wire at the five way terminal block.

Job done. Pity it took all day.

[roy mawbey]

Nice to see you found the wire described so clearly and where it was, with a photo. I even looked yesterday at the 356A wiring diagram for the carrera fuel pump. Couldn't see a reference but I guess although there was the carrera 'A' version probably more carrera 2 versions made. These were of course 12v. I even looked in my 'A' factory supplement workshop manual no mention there also.

That makes your modification really nice actually. Thanks for the explanation. Maybe Paul will tell us if they taped the spare wire to the loom in the same place on his 'A'. I am going to have to get my head under mine to look

Roy