308 gts dash led conversion

https://www.ferrarichat.com/forum/threads/what-have-you-done-to-your-ferrari-today.436876/page-109#post-147633922

A start...

 

yeah, that dash LED conversion makes a huge difference, even on the 328 !

here is another:
https://www.ferrarichat.com/forum/threads/dim-instrument-lighting-solutions.467204/

 

With the exception of head lights, I converted all other lights to led. Huge improvement on the alternator load. Brighter body lights, can even see them in the day. I run body lights all the time day/night.

 

I replaced my dash lights with LED. But I had an issue that I have not yet been able to fix.

LEDs are diodes, so if you install one in reverse, they will not light up - I guess the positive/negative was just done in reverse by Ferrari, for sake of convenience. So one of my LEDs did not light up. I tracked down something called "bipolar" LED that can light up in reverse. But apparently, as a consequence, it shorted something, so my oil pressure gauge, backlight, and warning light are now all out of commission.

To be fair, it looks like nobody else had that issue. Maybe the wiring on the 83 QVs were different from the other years? I don't know.

It is a bit of a pain to remove the whole instrument panel again, so I decided to let it be, for now.

 

I think if you had just rotated that LED 180 degrees you should have been fine.


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Actually, the LEDs are designed to be placed into the standard socket, so they can't be flipped. Here is an example of one.
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Here are before and after pictures. Other than the issue with the oil pressure gauge, I am very happy with the result. Image Unavailable, Please Login Image Unavailable, Please Login

 

No way I believe, that Ferrari flipped over polarity on this kind of sockets.
I believe, that your LED might have been faulty. They are coming from China and I had more than one faulty bulbs. Since one began smoking and glowing severly directly after installation, because of an internal short, I check each single item on my bench for a few hours.

Best from Germany
Marti

 

Here is the wiring diagram for the instrument panel. Bulb 16 is the oil pressure light. Gauge 41 is the oil pressure gauge.

I have not been reading schematics for a long time, but it looks to me like Ferrari did not keep consistent polarity on these bulbs. If you are using regular bulbs, of course, it does not make a difference.

I do remember that after our first try, some of the lights did not work, so we took out the panel, put in some reverse polarity LEDs, and it fixed everything except for the oil pressure gauge and lights.

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Does your dimmer work with the new LED's?

 

Good day Ron,

Most likely the original dimmer will not work properly with LED replacement bulbs. The reason is because LEDs are current driven whereas the original dimmer circuit is a voltage driver. To dim LEDs one has to appropriately set the LED drive current (not too high so the LED does not burn out and not loo low so the LED actually lights up) and then switch the current on and off at a variable rate (frequency). Varying the frequency will vary the LED brightness.

Cheers,

Sam

 

^ the dimmer did not appear to have any impact on brightness after I replaced my instrument lights with LEDs.


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I have found that even dimmers that CLAIM to work with LEDs often don't. Or at least they don't work consistently or as intuitively as dimmers/incandescent bulbs.

Since I rarely drive the 328 at night, it isn't worth the trouble to me but obviously, if you do drive one of these cars regularly at night, brighter dash lights would certainly be helpful.

 

Those are both good references. One of them refers to another thread by forum member magnum, it's this one:
"How to: dash lights", finally . There are multiple links in that thread to documents to download with great descriptions of the different types of bulbs needed, AND the modifications needed to several of the bulbs to make them work - it's not just polarity.

Again, it's not just polarity - several of the sockets won't work at all with an unmodified LED bulb, which will short out if not corrected.

I'll post my dash update notes here - back in October/November, I did an instrument panel cleanup and LED conversion on my Euro 84 QV. The stock instrument lights were very dim, and the grounds were not good - when I turned on the park lights and/or headlights, the oil pressure, fuel level, and coolant temp would all jump up a few needle widths! Also, my coolant gauge was not indicating nicely, it would usually show the engine running hot by 10*-20*, but occasionally drop suddenly to a more normal reading.

I followed Magnum's "HOW TO DASH LIGHTS GUIDE 11.pdf", along with the "LED Substitution Chart based on Magnum.pdf", both documents posted in the links above in my post or the earlier linked threads.

First note - when removing the instrument panel, other guides mention removing the 4 corner screws, then the panel just comes towards you and out. Mine didn't - the wire bundles under the dash didn't have enough slack, they were ziptied pretty good. There are three connectors that must be disconnected to feed the panel side of those wire bundles up to follow the panel out.
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I removed the speedo and tach from the instrument panel to manage the light replacements more easily, then went through EVERY wiring connector and bulb connector on the panel, cleaning with emery paper and contact cleaner, then using Stabilant-22a contact enhancer. The blades on the connectors all had a light white coating, shown below on the left side 2 blades vs the other 4 blades that I cleaned.
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The female connectors I gave a squeeze to tighten them up
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Example of one of the warning light bulb sockets, one blade cleaned and one as found
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Stabilant-22A contact enhancer - it's pretty magical, and priced like gold - the small bottle on Amazon is $67. It creates a very thin coating that promotes 100% electrical contact and prevents gradual corrosion buildup. Cleaning up the contacts and protecting them is just as important to getting good instrument panel lighting as is the LED bulb substitution (and to having instruments read correctly).
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For the Speedometer lights - the LED bulbs DO care which way they're oriented, they are polarity sensitive. To avoid having to plug bulbs in and put the instrument panel back, only to find bulbs not illuminating, I set up a bench power rig using a battery booster and old multimeter leads.
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Testing the polarity of an LED speedo bulb - power lead held to the blade in the red speedo wiring connector (left hand), ground lead held across the ground contact of the bulb holders.
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I had a 60% success rate in getting the LED bulbs oriented correctly (I had to remove and turn around 2 of the bulbs after they didn't light up on the first try).

Here's the 5 speedometer bulbs - the gauge lights are the 3-LED bulbs ("74-WWHP3" from www.superbrightleds.com), and the three other single-LED bulbs ("74-NWHP") are for turn signals and the lights-on indicator (the high beam indicator is on the tachometer face) The 3-LED bulbs give a broader light spread in warm white (which illuminated the gauge face as green), while the single-LED indicator lights are just lighting up the small coloured dots (turn signals, lights-on) on the gauge face and the cooler natural white works better in those.
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Speedometer lights and harness reinstalled to back of Speedo, ready to go back in the instrument panel

 

The 4 warning lights in the corners of the instrument panel - those are the tricky ones, where the bulb doesn't fit properly and must be modified. One warning - do NOT replace the incandescent bulb in the alternator warning light with an LED bulb. The alternator current circuit needs some resistance on that warning light to function correctly, and if you put an LED bulb in the circuit the alternator won't charge the battery?!!

Naturally, there was more to this task than just plugging in the bulbs and testing polarity. These 3 warning lights (not counting alternator, it's rear defog (spare in my car, as there is no defroster grid on the rear window), fan, and hazard warning lights) use a miniature wedge bulb, a 74-WWHP (warm white, otherwise the same as the natural white 74-NWHP used in the speedometer turn indicators and parking lights). While they plugged right in for the speedometer application (after checking polarity), they didn't actually fit in the bulb housings for the warning lights!

Here's one of those warning lights as pulled forward from the instrument panel, with a half-modified LED bulb posing in front of it:
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With the cover removed from the light, here's the light socket with the incandescent bulb in place - first problem, the 74-WWHP mini-wedge bulbs are slightly too wide to fit. Note how low the old bulb sits in the socket:
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This is an unmodifed LED bulb trying to fit in the socket - but it can't, it's sitting too high:

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This is the modified LED bulb, properly seated in the bulb socket:

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A Dremel is used to grind a very slight amount from each side above the wedge, to make the top LED portion the same thickness as the width of the wedge connector, for a few mm.

Here's three bulbs, from left to right - unmodified LED; double-modified LED; and original incandescent.

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You can just make out where the modified LED bulb was carved a bit narrower, but the first warning light photo actually shows it better - look right below the '1' on the '12VDC' printing, where the Dremel has carved a flat on each side of the round portion above the wedge base.

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Back to this picture, showing a modified LED bulb below an unmodified LED bulb. Aside from the Dremel trimming, the lower bulb is only showing 1 contact wire! The standard bulb has two contact wires, that each wrap around the base from one side of the wedge and come back up the other side of the base - in standard spec, there's a positive and negative wire contact on each side of the wedge base. While that worked fine in the speedometer bulb sockets, for some bizarre reason the panel lights have a different socket with a broad brass contact on each side, which would short the dual contact wires on each side. To make these LEDs work in the socket, we have to cut the wrap-around length off of each contact wire, so that there is only one contact wire per side (positive on one side, negative on the other, of course!) Then we're back to polarity matching, and naturally they make that more difficult than it needs to be - in the above picture, the black wire on the back contact should be ground, the brown wire should be positive... but inside the bulb socket they reverse those connections. Image Unavailable, Please Login After more messing with my power test rig to check the polarities, I was able to finish with those 3 warning lights.
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The lights in the three small gauges (3 gauge lights, a low fuel warning light, and a low oil pressure warning light) were regular BA9s base lights, with no polarity concerns - the sockets were wired properly for the bulb +/- orientations.

Old incandescent bulb in the socket, new LED bulb ready to jump in:
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Here's the back of the tachometer, with 5 light sockets. The 3 warning lights (high beam indicator, brake warning light, and rear fog light indicator) use the same BA9s as the small gauges, but again for some bizarre reason, the 2 gauge lights in the tachometer are different again - they need a BA9s-WW4-32 reversed polarity bulb Image Unavailable, Please Login Not hard to get (ww.superbrightleds.com) if you know in advance you need it, and luckily the DIY 308 owners have gradually built up a good list for these LED conversions.

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Last item before reassembly - bypassing the gauge lights dimmer rheostat.

Bottom view of the dimmer rheostat:

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Rear view of the dimmer rheostat = gauge lighting power comes in on the white wire, through the rheostat, then out the paired yellow wires:

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As with all the lighting and LED upgrades described, this is fully reversible - I built a double-male jumper wire, 2" long, to bridge the female connectors from the dimmer rheostat. Power to the gauge lights will now get a straight path for "maximum" brightness all the time (and I even picked the right colour wire to splice in Image Unavailable, Please Login ) :

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The last step before reinstalling the instrument panel was to add an additional ground point to the ground wire circuit on the instrument panel. The ground circuit through the instrument panel comes in on one of the main connectors. I followed the path through the instrument panel wiring to the furthest end, then used a Posi-Tap (the blue connector) to add a 14 gauge ground wire.

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For the other end of my new ground wire, I located an unused stud under the dash, and made a ring terminal/blade connector for it:

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Underside of the dash - reference dead pedal, clutch, steering column, brake - with my new ground point installed:

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Now with the instrument panel re-installed in the dash, the new ground wire is connected to the new ground point, and the I, II, and III wire bundles from the dash are reconnected to the chassis side connectors.

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The connector cleanup and additional ground wire successfully eliminated the gauges jumping when the lights were turned on, they don't budge now. The LEDs are brighter and pretty even now - it's tricky to get instrument lighting photos to come out properly, but this is a pretty good idea of what they look like now.
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Nice work Gordon. I am on the fence about the modification with regards to the fact that I never drive at night. Well, once last year. I certainly brightens up the gauges.

 

I've just done this LED conversion on my 83 qv and although my dash lights up fantastic, I have a problem....
For some reason when the head lights are up (headlamps off) all guages light up nice and bright. But once I turn on the head lamps, the speedometer lights dim a bit then dim even more when i turn the headlamps to high beam. The speedometer is still lit up ok, but definitely a weaker light compared to when headlamps are turned off.
Second issue is when head lamps are on and I turn the hazard lights on, the speedometer lighting dips off and on as the indicators flash.
All other guages remain perfectly lit.
I have run an extra earth and bypassed the dimmer.
Any help with this problem would be much appreciated.

Dean

 

Sounds like the ground to your speedometer isn't great (at least to the lights). Since only your speedometer seems affected, it's unlikely to be the ground connection to the entire cluster. It's more likely isolated to the ground on the speedo itself. Also, since *all* of your lights dim on the speedo, it's most likely the ground since it's the only thing that's common (pun intended) to all the lighting.

Check (and clean):
- The spade connector to the metal "curved bar" that runs along the bottom rear of the speedometer unit
- The black wire that goes from the curved bar to the red connector
- The spade connector for the ground (black wire) on the red connector

Also, the lights get their ground connection from the housing that snaps into that curved metal bar. It's generally a very tight fit, so usually provides a very good ground. However, might be worth a little "wiggle" or "twist" on those housings to ensure a good connection.

Lastly, if you have a multimeter or ohmmeter, check the resistance between the red connector ground spade pin and the metal curved bar on the housing. It should be very very small (less than 0.5ohms).

BTW, the other possibility is that your charging system isn't able to keep up with the load from your headlights so the voltage to the entire vehicle is drooping. I doubt this one, as the other instrument clusters should show the same dimming problem. However, a good check would be to raise/lower your windows and see if the speedo lights are dimming. The window motors draw a *lot* of current so if your charging system is struggling you should see the same issue when the windows are actuated.

 

Thanks Jason, I'll get that ground terminal cleaned up this weekend, and let you know the result.
Cheers.
Dean

 

I cleaned up the earth and fully charged the battery today. Everything is working perfectly, no more dimming lights.
Converting to LED has made a huge difference, well worth it.

Cheers for the help

 

Gordon,

Can you tell us how many of each type of LED you bought to do ALL of the gauges and idiot lights?

 

Not sure; I’ve driven lots at night. I’ve never not been able to read the instruments when I want to and TBH I quite like how they look. Reminds me I’m not in a modern car; feels nice and calm. Doubt I’d get the same feeling with bright white LEDs glaring at me!

 

Few notes Interior LEDs (dash + lighting):
- There is a choice in "temperature" of LEDs. Choosing a warm color LED preserves the original green hue of the 308 dash (looks very original). Choosing a cold color LED makes the dash more blue-ish (looks more modern)
- The intensity at night is brighter but not glaring or distracting in any way. Honestly, night time isn't really the issue -- the old incandescent bulbs were bright enough to read the gauges (altho the LEDs make it easier on old eyes)
- Dash indicators in the daytime are *significantly* better. Basically, during the day, it's very difficult to see the indicator lights (e.g. turn indicators, lights, oil warning, etc). The LEDs make them quite clear

One note about Exterior LEDs (headlights + indicators):
- LEDs make a major difference in safety. The difference in indication is *massive* for things like brake lights, turn/hazard indicators, etc. Massive. And the LED headlights are so much better than the incandescent for illumination. They aren't better than the HIDs from an illumination standpoint but unlike HIDs, the color of the LED light can be chosen to keep the vintage look.

Final note about LEDs:
- Changing over to LEDs reduces the load on your charging system substantially. The entire stock interior lighting package is around 50-60W; changing over to LED drops that down to less than 10W. Typical stock headlights are about 150-160W; the LED replacement is less than 25W.

Better visibility, higher safety and lower electrical load -- with zero modifications? It's a pretty compelling. The biggest downside is that while most bulbs are plug-n-play, some of them require slight modification fit in the sockets.

Apologize for the crappy pictures, but here's a few from my change-over last year:
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LED dash at night...sorry didn't capture a stock picture before LED replacement. The diff't color on the tach is the camera--all of the gauges have the same illumination and hue. Also, you'll note the foggy lens on the clock in lower left -- stupid plastic lenses.

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Turn indicators (left - LED, right - incandescent)

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Brake lights (left - LED, right - incandescent)

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Parking lights (left - incandescent, right - LED)