Hi everyone, have searched the forum for this subject but can't find much, so would like some input... I have a 1986 412, in great shape. However, the interior gauge lights are so dim even with the rheostat turned up as far as it will go, that I simply can't see the gauges at night. The existing - presumably original - bulbs give no adequate light. I also think the light output for the rear tail and brake lights, as well as the front side lights and (yellow bulb) front indicator lights are lousy - and considering newer cars all have daytime running lights and high mounted rear brake lights as additional warnings to other vehicles, I feel my car is becoming invisible and perhaps liable to being hit by not being seen by other drivers. SO, am looking for guidance on changing the existing incandescent bulbs to LED bulbs, both for the gauges, and also for the exterior front/tail/brake and indicator lights (which will require also a new flasher unit due to lower circuit resistance with LED bulbs). The LED bulbs claim to be brighter, use less current, and produce less heat. I have been in touch with Gil at Quicksilver Automotive and his advice seems to suggest I would gain what I would like and should do it. It doesn't seem to be very costly.... OR, can I replace the 5W bulbs with 21W bulbs for more light, without them getting too hot, melting the lenses (much too expensive to replace even if available) or screwing up the wiring or blowing fuses? Thoughts? Recommendations? Concerns? Has anyone done it on their car? Thanks, Oliver
I've upgraded some of the lamps on my 348 but none of the instrument cluster lamps yet. The light provided by the original dome fixture (supplied by a pair of festoon lamps) was so bad that I experimented with various LED replacements before finally deciding on warm white LED replacements from www.superbrightleds.com The result was light output that is at least double that of the original filament lamps but is otherwise indistinguishable from stock. Standard cool white LED replacements resulted in a harsh, garish light that I considered completely unacceptable. Since I've finally found LEDs that meet or exceed my expectations I'm in the (slow) process of replacing the rest of the lamps in the car. Things I've learned so far: Don't trust the application guide for your car. Do your own research, including measuring the sizes of lamps for yourself. Warm white is the only acceptable LED color if you want to retain the OE appearance (and don't wish to have your eyes assaulted by a color akin to a cool white CFL 120V lamp). When replacing exterior lamps with colored lenses use the same color LED lamps (i.e. red for stop, amber for turn signals, etc). Use the largest, most diffused lamp that will physically fit in the housing. Smaller lamps concentrate the light energy over a smaller area and therefore look less natural. If you take your time and do your research I think you'll be very happy with the results, at least as long as you choose the color of the LEDs carefully. My initial experiments with cool white LEDs were terribly disappointing. Good luck and let us know what path you wind up choosing.
Thanks Mike, that's very helpful, especially on the colour characteristics of the LED bulb light produced. Appreciate it!
Note that unless you buy special reversible LED lamps the polarity of the wiring to the lampholder may need to be reversed. This was the case with several of the instrument lamps on my 328. This applies to the bayonet type fittings.
Look around in the 308/328 section; a number of people have shared their impressions of various LED options/sources. I suspect the fixtures in your car are quite similar.
Great info Mike. When I tried the LED festoons (also from superbrightLED), I think they only had the "natural" color and they looked totally wrong. Glad to hear the "warms" work. Do you have any problems with the directionality of the LED festoons? The normal festoons distribute light evenly 360 degrees, but the LED festoons I tried were far more directional because the LED's are mounted on a paddle 180 degrees apart.
Also, very good advice to measure the bulbs. I ordered them by bulb type and the LED's were definitely of differing sizes.
The easiest fix for the gauges is simply to make a jumper wire and bypass the rheostat, which by itself, seems to pull some voltage out of the circuit. I did that on my previous 328GTS to good result. Not dramatic, but definite improvement. I also did the bulb upgrade to brighter incandescent bulbs...there was an online tutorial years ago for which bulbs to obtain for the tach and speedometer.
Peter, the festoon lamps I used in my 348 overhead light were the same style-- all of the LEDs are mounted on a board and are pointed the same direction. The 348 interior fixture holds two lamps and it's pretty large so I addressed my concern for light dispersion by ordering the largest available lamps, which of course have the most LEDs. The end result was (pun somewhat intended) brilliant. Light dispersion is better than stock, color temperature is the same as stock (you'd never know the interior illumination is via LED), and the illumination is way, way better than stock. I did notice light dispersion issues during my early experiments with LED festoon lamps where all of the SMD LEDs were contained within a tube like the original filament was. The LEDs are so bright they become much more noticeable if they're concentrated in a small area so I suggest using the largest lamp that will physically fit the housing. I can see possible issues with light dispersion in situations where the lens isn't flat but even the map lights in my car, which only have a small aperture to confine the light to a small area, are brighter than stock now that I've fitted bayonet base LED lamps with most of the LEDs pointing 90 degrees away from the aperture. To me the biggest issue is colorif the color is not right it calls attention to the lighting, which makes light dispersion issues more noticeable. But if the color is right you dont pay much attention to the lighting unless there are major dispersion issues. Sorry I don't have any pics right now. I'll try to get some one of these days, although it's not easy to photograph. In any case, I couldn't be happier with the results now that I've got the right size and color of lamps fitted.
Your insight has been very helpful. Warm white seems to be the way to go. I'll keep you posted. Many thanks, Oliver
Great info again Mike. Thanks. This is a great point. I cleaned up my rheostat with Deoxit contact cleaner and conditioner and it made a pretty big difference. Bypassing it will probably help even more -- lord knows you don't need a rheostat, at least with the stock bulbs. You probably will need the rheostat with LED bulbs (if proper LED's exist). On 330gt.com, Kerry talks about replacing the stock instrument bulbs with slightly higher wattage incandescent (I think stock was 3 watts and he increased it to 4, but that's from memory). That substitution did make a difference and didn't run too hot in his experience. LED's will definitely be brighter and run cooler if they make proper replacements (warm light in the correct size).
Putting higher wattage lamps in often has the opposite effect of what is wanted; higher voltage drop actually reduces the amount of light. Think of going up hill and shifting from 4th to overdrive.
The only issue I would have with LED is the cooler (bluer) color temperature may not look period correct on a vintage car.
The pair I installed on my 308GTS, as with several other owners, are very white...no blue at all. I am very happy with them. Some people have an issue with the bifurcated lens. Doesn't bug me at all. Image Unavailable, Please Login
Just a heads-up should you decide to do the headlight bulbs- I did LEDs on my truck, and the point of aim and beam pattern changed considerably from stock. Low-beam to high-beam 'considerably'. Other than that, I quite like them. Mine came with filters to make the color progressively more yellow. Literally, sheets of plastic tinted yellow. Nice. -Dave
I'd did my 328 with regular led,s no problem at all very bright now but you have to test them all when the cluster is out because the only work one way if you have a dark one just flip it over and you good.you can also dimm them if you like,very easy change and very low amp.
