I know some folks have been waiting to see how I mounted the Xeno 5W bulbs to the 3/8" copper pipe so they will fit into our 911 gauges, here is a quick picture of one

http://forums.pelicanparts.com/uploa...1165027901.jpg

Here is a almost finished product

http://forums.pelicanparts.com/uploa...1165027939.jpg

The bulb is attached with epoxy to the pipe and the ground wire from the bulb is soldered to the pipe. The power lead has a male spade terminal and the entire pipe is filled with epoxy.

I know a few folks have expressed intrest in how I was going to fit these bulbs into the gauges, now you get the idea.

I have lots of pics of the procedure just need to find the time to update my document. Hopefully next week.

Platas, please tell us more - exactly what LED bulbs are you using? Where did you get them? Are they really brighter than the stock bulbs? I started by first trying LED bulbs, tried many and none seemed to work because they seem to direct light only out the front of the bulb. Do you have any pictures?

Thanks.

As promised I have updated my Word Document with the procedure on howto prepare the 5W Xenon bulbs so they can be fitted to the gauges. You can get the updated document here:

http://members.cox.net/widebody/

Next I'll start working on procedure for building the new wire harness to replace the stock one for the bulbs as well as howto put the bulbs into the gauges and wire then up.

Stay tuned.

Great write up Sal! Keep it coming!

Last night the weather was nice here in RI and I took my 911 for a ride at night. I have updated the lighting in my Clock and Speedo with the Xenon 5W bulbs and the results are truly amazing! I really did not notice the diffrence that much when I took the picture:

http://forums.pelicanparts.com/uploa...1165601168.jpg

But after driving the car at night I have to say the clock and speedo are bright! Real bright! at least 100% more light in them. I think this is the answer to lighting these gauges. The modification is not real easy but is well worth the time all you need is time and proceed slowly! I have the write up on howto prepare the bulbs done and am currently working on the how to build the new wire harness and wiring section of my document. It's slow going right now because I have to many other things going on. You can get my current doc from http://members.cox.net/widebody/

Sal,

Nice work!

I got involved with this issue a while back when I was able to secure higher wattage guage bulbs from Germany. Unfortunately I could not see any difference in lighting.

My next thought was to take lower voltage incandescent bulbs and overdrive or use lower voltage Xenon bulbs and reduce the voltage to the harness.

I see you use 12v Xenons but would it be possible to use lower voltage bulbs and reduce the voltage as described above? As I'm sure you're aware they come in many voltage variations....3v, 6v, 9v etc.

This may make the retrofit easier.



***Edited for clarification.

Rick..I'm not following the logic with using a lower voltage lamp and then running them at a higher voltage...they will cook themselves to death. I like Sal's approach to this problem and I hoping once all this holiday business settles down I will have some time to experiment with the Xenon lamps and a BA9 replacement 'super white wide angle' LED that I found online. I would also like to try to attach the Ba7 base to Sal's brass tubing.

Ron,

Running at a higher voltage with incandescent bulbs was an idea that I pretty much dismissed (Sorry for the confusion).

What I'm suggesting is to utilize lower voltage Xenon lamps and reduce the the power to the harness. Not sure about the easiest solution for this, perhaps a step-down transformer. My thought is that the stock wiring and dimmer may be utilized as the result of less demand.

Ron, I looked at the details to buld a new harness to replace the current harness for the BA7 bulbs and it's a walk in the park. It is very easy to replace the old stock harness (put it on the shelf) and plug the new one in place of the old one. I think this will be simpler than trying to adapt the old BA7 bulb base to the copper tubing on the new bulbs. Just my oppinion on this of course.

Sal..were you able to test the 'donor' dimmer?

Ron,

Did not get the dimmer yet but it's in the mail. Should be here this week.

Do you have any 1 or 2 ohm hi-watt resistors? I figure I'll need a few for load testing. The resistors with the metal cooling fin cans.

Will keep you posted.

Hmm, let me check. I had some for the footwell circuit work I did last year.

subscribing to the thread for later use

5 watt is 5 watt, if you use lower voltage bulbs you will raise the current instead...

I mean no disrespect here to anyone, but my EE education and background has taught me that 5W is not always 5W allow me to clarify: The Xenon bulbs are rated at 5W when running at 12V and the formula for wattage is V x I = W (Voltage x Current = Wattage) so this means that wattage is a direct function of voltage and current. So for the Xenon bulbs the formula looks like this: 12V x 0.417A = 5W . Now if we increase the volatage in this same bulb to say 15V and you place an ampmeter to measure the current the current actually goes up because you are overdriving the bulb and not running it at it's specified voltage, wich in turn drives the wattage up, in summary if you increase the voltage the current increases and so does the wattage. You can actually think of wattage as a energy consumed and if you overdrive a bulb with more voltage it gets hotter indicating it is consuming more energy.

The above is a very quick summary of wattage and I have not discused resistance in the explination as it gets complicated in the case of a light bulb because it changes as the bulbs element gets hotter and does not work exactly like a resistor. For those curious I calculate the resistance of this Xenon bulb some where around 29ohms. the formula is I x R = E (Current x Resistance = Voltage) for this bulb it looks roughly like this 0.42A x 29ohm = 12.2V. Keep in mind that resistance (ohms) is the one Electrical component that does not change (but with bulbs it changes some due to heat) so as you drive the voltage up and the resistance stays the same you drive current up thus driving the wattage up.

What does happen to resistance as the bulb gets hotter? it actually goes down and this condition is known as thermal runaway and is why any electrical component that gets hot and is allowed to excced it's power ratings is so dangerous. It is this characteristic that leads to fires! It is also why over-driven bulbs burn out so fast. Once you reach thermal runaway this is what's going on: the component exceeds it's power rating and is now hot so it's resistance goes down but if the resistance goes down the current goes up, component gets hotter and then the resistance goes down further leading to even more current ... you get the picture. (And all the while the voltage can remain the same) eventually (very quickly) the component goes up in smoke!

Hope this makes sence.

What I commented was that RickM mentioned using "lower voltage Xenon lamps and reduce the the power to the harness" and drive them with a step down circuit on the lower voltage setting.
A 9 volt 5w bulb would then use 0.555 A instead of 0.417A. That would increase the load on the harness.

Safe,

Sorry, I missunderstood. Thought we where talking about over driving the bulbs. You are correct a 9Volt bulb rated for 5Watts is by design going to draw more current. But it is still 5Watts as you say.

Just wanted to be sure folks understand the danger of overdriving any electrical component with more voltage.

Ron, I saw that post and your pictures this is why I asked.

Guess who forgot to look?

so after going through this thread, do you have to make a new dimmer or can you use the stock headlight switch?

Thanks