M. Requin

One of the things I have least liked about my 928 is the unsatisfactory instrument lighting. I have read a number of threads about improving this situation, and I finally decided to use electrolumiscent panels from SpeedHut, Inc. (no affiliation), coupled with fluorescent paint on the needles and UV LED replacements for the main dash illumination bulbs. (That's why "photoluminescent" - fluorescence and electroluminescence are subsets.) The big problem with the SpeedHut dials is that they are not available for an 86.5 auto, just the manual. So I had to modify the tach dial which has the gear indicator lights. I spoke with SpeedHut (good folks) and found I couldn't just cut out an arcuate section, because that would sever a conductor. I decided to punch holes over the gear selector lights (I did not want to just cover them up, I find them really useful at times). I was advised to use a sharp punch - HF to the rescue - see the pics. A related problem is that the tach scale is different between manual and auto. Still working on that one (suggestions welcomed!). The other change I made to the EL gauge faces was to cut out the clear plastic on the smaller gauges. They are supplied as complete plastic disks with an EL overlay, but I didn't want reflection from the uncovered surfaces. I cut them out and used permanent marker on the edges to kill that little bit of reflectance - works great. I also had SpeedHut make up the two smaller faces with no central cutout - there isn't one on the right, and the one on the left is for trailer turn signals. Wish I had kept that one, because the harness attachment for the tach dial power obscures a good part of the standard turn signal indicator, so I could have rewired the instruments to use the trailer turn signal indicators instead. Future revision. One of the pics shows how I used the mounting screw holes on the gauge face to get the register correct for installing the new face, and another shows how I used a copy of the face as a guide when punching the holes. The registration of the holes with the indicator lights isn't perfect, but I'll live with it, at least for now.

Benchtop mockups of the instruments showed just what I was looking for. Time to deal with the needles, since of course they are not electroluminescent. I thought I would use a combination of fluorescent paint on the needles and UV LED's for the lighting. One of the problems, as you can see from a pic below, is that the lucite light guides that take the light from the bulbs to the dash face are mirrored, and at least on mine, that mirroring was gone. That's one contributor to bad illumination. If you look at the "installed" pic below, you can see I chose a white paint (fluoresces bright blue) for the needles. It all looked good on the bench, but when everything was put back together the needles hardly moved when the car was started! Too much weight from the paint! Out they came to have the paint scraped off. The next iteration will use a different kind of paint, so this part is still in progress.

Bottom line, I like the looks, I love the legibility. I'll be interested in all feedback, + or - .

Brad W

WOW that looks cool.

Airflite40

ummmmm the 2 tachs do not match up.

when the factory tach is at 4000 the speedhut one is at 4500. FAIL.

M. Requin

ummmmmm, indeed. That's what I said: "A related problem is that the tach scale is different between manual and auto." And I'm working on it. To be posted when I have it solved. BTW, sounds like this is something you would be concerned about since you posted about it, so a question - if you had to choose (and I don't think it will come to that, but anyway), would you want the bad-scale tach to be accurate at idle, or at redline? Just curious.

fraggle

Neat project. Good luck with the scaling issue.