What is the best way to increase brightness in gauges?

[scarceller]

Originally posted by Mysterytrain
Sal, I really like the write up. I don't have the wiring schematic in front of me but here is a thought..maybe Warren will jump in. Why not trigger the the relay from the parking light terminal on the OEM light switch. You could grab this connection from the switch or the fuse panel. For those of use that never need the dimmer we could omit the K8004.
I'm also wondering if the OEM dimmer can be used with K8004 in place of the external pot?

Ron, Wow I had the same thoughts. It would be nice to try to use the current OEM dimmer with the K8004. I'm just not this far along yet. I'm trying to first get the Gauges lit with the 194 bulbs.

I'm also with you on just wiring the relay and not bother with dimming. But hopefully we get these gauges bright enough that we need to dim them. Wishng here of course.

Keep the ideas coming, we'll keep at it.

[Mysterytrain]

I was looking at the info sheet PDF's for the K8004. I think this modified circuit will work:

[scarceller]

Originally posted by Mysterytrain
I was looking at the info sheet PDF's for the K8004. I think this modified circuit will work:

Ron, great this allows the stock dimmer to work. Also would you power the relay from the parking lights? You did not change that.

[SCWDP911]

As a newbie to 911's, I wondered if the fuse panel has anywhere for a spare setup that we could make the battery connection through the 5amp fuse in the circuit involving the relay and K8004, using a stock (spare) location in the existing panel to tie it in. Can't look in my car at the moment, but will later tonight. Just figured one of you would know off top of your heads.

Just thinking about a way to minimize and keep things as stock looking as possible.

[Early_S_Man]

Sal & Ron,

There are a couple of reasons I don't plan on using the dimmer rheostat built into the light switch:

1. The rheostat in my car tends to be 'spotty' and scatchy/coarse in its' adjustment of instrument illumination ... cleaning might improve the performance, but I have my doubts. Anyone who examines a dimmer rheostat from an older car will note that localized heating tends to cause the wirewound Nichrome coils to spread apart a bit at the location where the wiper resides most of the time ... the oxidation increases resistance at the contact point and increases heating, which causes some expansion of the coils, which tend to spread apart more, and causes the adjustment to be more coarse than when the rheostat was new and all of the coils were uniformly tight and close together.

2. The input control of the Velleman K8004 kit needs to be in the configuration of a Voltage divider, so a resistor to ground would need to be added, and that resistor would need to be determined empirically for each car to suit the owners' needs for a satisfactory dimmer range.

My feelings are that a 3-turn potentiometer would be perfect to give a precision 'feel' to the dimmer, unlike the dimmer control in many older cars.

ps,

My dimmer tends to be used in one of two positions ... 100% and around 75% for when my eyes aren't adjusted to the dark, and later when they have adjusted and the pupils have dilated. Most of the time the control resides at the lower setting for longer night drives.

For owners wanting to maximize instrument lighting levels without getting into modifications ... the bulb holders and Faston connectors and tabs should be thoroughly cleaned, in addition to replacing the old bulbs. From older threads, a few hints:

1. Remove your bulb holders one at a time and clean & polish both the Faston tab and the holder body with HD rubbing compound or metal polish ... until bright and shiny brass is all you can see. Clean the Faston cnnector at each bulb with vinegar and old toothbrush, then rinse with distilled water ... you should see slight 'pink' coloration of the copper in the brass alloy! Put a small amount of Dow Corning 4 or 111 Silicone Grease on the tab and Faston connector and reconnect.

2. Clean the ground tab and connector at each instrument and treat with silicone grease. This diagram provides some hints as to what needs to be done to older Faston connectors:



3. Replace the bulbs.

Improvement should be quite visible!

[quattrorunner]

Very good writeup. I'll follow it and make the improvement

[SCWDP911]

Originally posted by Early_S_Man
Sal & Ron,

There are a couple of reasons I don't plan on using the dimmer rheostat built into the light switch:

1. The rheostat in my car tends to be 'spotty' and scatchy/coarse in its' adjustment of instrument illumination ... cleaning might improve the performance, but I have my doubts.

2. The input control of the Velleman K8004 kit needs to be in the configuration of a Voltage divider, so a resistor to ground would need to be added, and that resistor would need to be determined empirically for each car to suit the owners' needs for a satisfactory dimmer range.

My feelings are that a 3-turn potentiometer would be perfect to give a precision 'feel' to the dimmer, unlike the dimmer in many older cars.

Warren, you bring up good points as usual. I think the beauty of this is that it can suit the needs of many. Some of us really do not think that the dimmer switch is needed at all. Some of us would like to keep it as stock as possible, but enhanced. And some would like to make it "perfect". It kind of seems like a small thing, but I think this really is one of the best threads I have read. It will be interesting to see the end "products". I hope everyone continues to share their successes and failures with this project.

[Mysterytrain]

Sal, I realized after I posted the modified circuit I didn't change the solenoid power source..I was a t work..sometimes I feel like I work for Pelican.
Warren has made good points. If and when I go this route..actually WHEN I go this route I doubt I would use a dimmer at all...I don't recall ever using one in any car I've ever owned. I like the idea of 'enhancing' what is there and have my mods being reversable..no extra holes!

[scarceller]

Update on Bulbs: I have compared the stock 191 bulb to a 191 Xenon Blue bulb in my clock and speedo and the Xenon bulb looks the best, it looks super bright white light with hint of blue, very modern look compared to the yellow stock look. You can get these bulbs at Walmart for about $5.00 pack of 2. Of all the 191 bulbs I have tried this one produces the best results. It is rated 12V 5W slightly higher wattage than the stock 191 that has 3.8Watts. I'm in the process of trying this bulb in all gauges and will provide more pics.

I also have figured out that the stock harness for the stock BA7S bulbs is just a big octopus like configuration that has all the holders for the stock bulbs on one end and then has all the wires joined together at the other end with a spade plug. This is great news since it's real easy to just remove the octupus like wire harness and build a new one for the 191 builds. This allows non invasive modification of your harness so that you can easily return to stock harness. I will provide more pics for this soon.

I know others are looking at trying diffrent bulbs so figured I post this quick update.

Also track progress via this master document:
http://members.cox.net/widebody

[Mysterytrain]

Morning Sal...Here is another thought. Someone awhile back had LED's made up with BA7S bases. If that could be done with the 191 bulbs it would make for a very clean install. The problem is: I'm not sure what the current draw is going to be with the complete set of 191 and if the OEM harness can handle it. Then again, it might not be a bad idea to fabricate a new harness with the SAME color code but larger gauge wire. Ok, so now we need a donor harness..3rd cup of java here! zoom, zoom

[BertBeagle]

Originally posted by safe
A little off topic but, has someone done a fix for the high-beam blue light?

Looking for the same info but don't think anyone has offered anything up.

My blue high beam light is hardly visiable.

Anyone else have this problem?

Thanks

[SCWDP911]

Originally posted by BertBeagle
Looking for the same info but don't think anyone has offered anything up.

My blue high beam light is hardly visiable.

Anyone else have this problem?

Thanks

yep

[cicsprog]

How Many Pelicanites does it take to change a light bulb? Good thread guys.

I changed mine out with:

http://www.superbrightleds.com/cgi-...cgi?product=755

Don't bother. My Speedo stopped working after changing (gear must have finally croked). No good deed went unpunished.

Jason
88 CAB

[SCWDP911]

Originally posted by cicsprog
How Many Pelicanites does it take to change a light bulb? Good thread guys.

Good one!

[Mysterytrain]

Sal..here is a bit more brain storming for your project. According to the book of Bentley, terminal 58A shows three connections via two spade connectors attached to it.
There is a spade connector for the hazard flasher light and a second spade connection for the instrument light harness made up of the 8 bulbs for the gauges. A second wire is crimped to that same spade connector for 4 more bulbs. 3 bulbs reside in the fresh air control mounted on the dash and one additional bulb for the heater light inside the square bezel on the tunnel by the heater levers. Why the hazard light is on a dimmer I will never know. The fog light switch lamp and the rear window defroster lamp do not dim. The gauge of the wire is .5mm which is equal to 20 AWG and can handle 11 amps.
The bulbs you are planning to use draw .27 amps so lets round up to .3 amps. If you replace all 12 you will be pulling 3.6 amps, the harness will still be happy but I wonder about the switch rating?? My suggestion would be to do some re-connecting of the harnesses.
I would move the hazard indicator light harness and the harness that feeds the fresh air blower lights to terminal K on the switch. This would also be a good place for a fuse. Terminal K is hot when you are in parking lights or headlights mode and in stock form appears to only be powering the ashtray light. Since there is no dimming from this connection it would also be a nice place to grab 12 volts for the relay solenoid that you are planning to add. If current draw is a concern, the fresh air lamps could be replaced with LED's . If you have ever attempted to replace the fresh air panel bulbs you will agree this is a great place for something that will never burn out again in your lifetime. Again, none of these lights will dim {I don't see why they need to}.If they are left as BA7s the 5 lamps will draw about .5 amps total from terminal K, of course LED's would be much less.
Another option is to use terminal K to trigger a relay and power everything from that relay.
A note: Bentley shows the rear window defogger light and the fog light indicator tied to the dimming harness..this is incorrect. [at least for my car]
Anyway, now the only connection left on terminal 58A is the instrument lighting harness consisting of 8 bulbs. The factory had 13 lamps tied to 58a. If I base the load capacity of the switch on 13 -BA7s lamps @ 100ma each it comes out to total 1.3 amps. So the question goes back to how much current can the switch safely handle. Terminal 56 on that same switch feeds power to the headlight flasher switch. From the flasher switch it goes to an 8 amp fuse. Can we assume the headlight switch contacts all have the same current capacity? Something like 5 or 8 amps?? Can the OEM dimmer circuit handle 4 amps? As much as I would like to wire 8, 191 bulbs directly to the dimmer I think the safest engineering approach is to use the AUX dimming module that Warren suggested. I'm trying to track down a potted dimmer module, I'll keep you posted on that quest.

[Mysterytrain]

cicsprog..been there done that..got the super brights in my car. They are a very minor improvement. The problem with LED's is that they are directional and don't spread the 'better' light across the face of the gauge. The plus side is the minimal current draw. Another LED option are the ribbon type that can be curved around the inside of the gauge. Bring money and it requires disassembly of the gauge.

[scarceller]

All, I have not reported any progress in a few days because this week I'm on vacation. I'm still working on our gauge lighting mod. I have built new bulbs from 194 Xenon bulbs (Walmart) and this time I created metal bases for them using 3/8" copper tubing. 3/8" is a perfect fit for the tubes in our gauges! I used epoxy to attach the copper tube to the bulb. Will post pics soon, for now I'm still testing.

Ron, thanks for the tips on the final wiring.

[scarceller]

Did more work on my gauges tonight: This time I updated the stock 2W bulbs in the speedo with Xenon 5W bulbs and I really like the results, the 5W Xenon bulbs came from www.bulbs.com part #B715205
I think this is the solution to our gauge lighting improvement! I plan to go with these Xenon bulbs as the solution for my car. The gauges look stock just much brighter. The other bulbs I liked where 194 blue bulbs from Walmart as they produced a color that looked more modern resembling HID lighting (slight blue tint) but I think I like the Xenon bulb better and it's a better fit into the gauge as well.
here is the result:



The Tach has brand new stock 2W bulbs while the Speedo has the update 5W Xenon bulbs. Not sure if the picture does the Speedo justice but the speedo is much brighter, I'd say at least 50% more light.

The 5W Xenon bulb is smaller than a 194 bulb and fits into the tube(s) in the gauges much better than the 194 bulbs I had been experimenting with.

Also, I have discovered that 3/8" copper tubing is a perfect mount for the bulbs as the tubes in the gauges appear to be 3/8" diam. I will update my document with howto mount he xenon bulbs to the 3/8" copper tubing soon. For now I thought I'd share the picture of the results.

[rfuerst911sc]

Nice work! I assume the 5w Xenon bulbs can be dimmed with the dimmer? Any pics of the 3/8 copper tubing cut to size in your install?

[CBRacerX]

Sal - I think you are really on to something, thanks for sticking on the case so diligently!