DDK - Die Deutschen Klassiker

This looks like a great upgrade!

Can I just confirm before I order - how many back-lighting bulbs do we need in total for the 5 gauges please?

I think there might be a dimming knob - does that still work the same with the LEDs?

Thank you all for the tips!

That is impressive!
How many did you order please?

I bought the set of 9 that Peter linked to:

https://www.classiccarleds.co.uk/produc ... 9086756973

I only fitted 7 for back lighting, but I guess that you could use the other 2 for full beam, low fuel or brake warning?

Dean - I didn't think of trying the dimmer, but will next time I am in the garage.

No one noticed my clock delete?

After having a few electrical issues I decided that a voltmeter would be a handy addition. I didn't want one looking like an obvious bolt on and even thought about putting one in the glovebox - but then it wouldn't serve much purpose if you couldn't see it all of the time. I had seen that North Hollywood Speedo do a few custom gauge conversions but I suspect that these would be big ticket items. I ended up buying a T fuel gauge off of Matt and fitted an early 924 voltmeter inside the housing. I'm going to use the warning light as a low oil pressure idiot light - I have got the dual pole sender, just need to find the 'sporto green wire' to connect up to.

Clever stuff

got to say , I like the gentle amber glow of the original bulbs when heading back up the motorway on a dark cold evening, heater on etc , something quite romantic about it

Ralph wrote:Installed my LEDs today and it certainly looks a lot brighter. I only upgraded the illumination and not any of the warning lights - I may revisit this though.

Great pic.

I was convinced the dimly lit, warm glow of someone smoking a Player's Navy Cut on a wet night was the look to go for on dash lighting but now I'm not so sure...

As half the gauges are out it would make sense to change them.

Do you know of the dimming function still works when the LEDs are in?

Sent from my SM-G981B using Tapatalk

Just checked the dimmer and it doesn't seem to make much if any difference.

Ralph wrote:Just checked the dimmer and it doesn't seem to make much if any difference.

Thanks for checking, now that has crept onto the jobs to be done list I'm going to put some new standard ones in as only a few pounds on Amazon and see how I feel about those as quite like the idea of being able to dim them.

Sent from my SM-G981B using Tapatalk

Ralph wrote: ↑Tue Jan 17, 2023 8:59 pm Just checked the dimmer and it doesn't seem to make much if any difference.

I suspected that this might be the case. I did some rough calculations, and worked out that the original dimmer electrical resistance built into our headlight switch would have been in the order of about 1 Ohm. In the LED bulb equivalent circuit (as part of what we call a potential divider), that resistance would not change the brightness significantly. For anyone that felt the need to reduce the brightness of the LED dash bulbs, a 100 Ohm variable resistor, or a fixed resistor, wired between the bulbs and the knob would do the trick...

deano wrote: ↑Thu Jan 19, 2023 10:05 am

Ralph wrote: ↑Tue Jan 17, 2023 8:59 pm Just checked the dimmer and it doesn't seem to make much if any difference.

I suspected that this might be the case. I did some rough calculations, and worked out that the original dimmer electrical resistance built into our headlight switch would have been in the order of about 1 Ohm. In the LED bulb equivalent circuit (as part of what we call a potential divider), that resistance would not change the brightness significantly. For anyone that felt the need to reduce the brightness of the LED dash bulbs, a 100 Ohm variable resistor, or a fixed resistor, wired between the bulbs and the know would do the trick...

Don't think that I've ever used the dimmer - but then I've not driven my car at night much!

I didn't mention it earlier but whilst working on the speedo I had the small issue of smoke coming from within the dash hole - this turned out to be coming from a smouldering dash iliumination wire. I presumed that I had snagged the wire and it had shorted out. I replaced the damaged piece of wire and carried on with replacing the bulbs.

At the time I thought that it was odd as no fuses had blown but it turns out there is no fuse for the dash illumination. I searched around a bit and found that there is an easy modification you can do - install an in-line fuse.

http://forums.pelicanparts.com/porsche- ... ation.html

https://www.early911sregistry.org/forum ... LIGHT+FUSE

I mentioned this to a Jez at Carrera Performance today and he pointed out that when you install LEDs it is important to make sure that they are seated squarely in the bulb holder as they are taller than the standard bulb and when you push them into the gauge housing the taller LED lamp can short out on the side of the housing and cause the melted wire (or worse!). Also to be carefull that they don't drop out of the holder and then roll around inside the gauge.

Another small job to do......

Top tip!

As mentioned by Ralph, it's a really good idea to add a fuse to the gauge bulb circuit. Later models may be better, but large sections of wiring harness on my early car aren't protected. Such an easy fix to avoid the wiff of an electrical fire .

chris68 wrote: ↑Sat Jan 21, 2023 10:02 am As mentioned by Ralph, it's a really good idea to add a fuse to the gauge bulb circuit. Later models may be better, but large sections of wiring harness on my early car aren't protected. Such an easy fix to avoid the wiff of an electrical fire .

All that's required:



Just remove the black/blue wire from the back of the headlight switch and add this in the line. I used a 2 amp fuse, didn't have any black/blue wire so purple will have to do.

Hopefully no more smoking dash wires and panic attacks.

And if you can't make one up for yourself for 15 euros you can buy one off of Kroon:

https://www.kroonwireharnesses.com/pors ... -1965-1989