How do I make my instrument panel lights brighter on my 308/328?

Many 308 and 328 owners complain about the brightness (or lack of brightness) of their instrument panels. When driving at night, the dimly-lit gauges in these cars are hard to read at best, and impossible to read in many cases.

This issue can be remedied with a small amount of effort by simply replacing the bulbs behind the gauges with brighter ones. To do so, simply follow these four steps:

  1. Using a tempered 3mm allen wrench, loosen and remove the 6 hex bolts around the horn button on your steering wheel. Do not use a standard size allen wrench, as the hex bolts are metric. Be very careful as you loosen the hex bolts, as too much force may break the heads off. If you experience difficulty, you may try applying some Liquid Wrench to help loosen the bolts. Once the bolts are removed, pull off the steering wheel and set it aside. If you do happen to damage the bolts, 5mm bolt replacements can be obtained through any store that carries Momo steering wheels or, of course, your local Ferrari dealer. If you'd like a cheaper solution, an American #10 x 32 thread allen bolt has the exact same thread as the original bolts. It uses an 1/8" allen wrench. The American bolts look identical, and you can find them at a local hardware store for less than 15 cents each.
  2. Next, using a screwdriver, carefully pry out the warning lights in each of the four corners of the instrument panel. Behind the four warning lights that you just removed, you will see four screws inset about two inches into the dash. Remove these screws and the instrument cluster will come out easily.
  3. On the instrument cluster you just removed, you will see a total of four bulbs - two small bulbs that light the speedometer and two large bulbs that light the tachometer. Remove all four bulbs and replace the two larger bulbs with Sylvania bulb #3893 and the two smaller bulbs with Sylvania bulb #2723. While the #3893 can be found at just about any auto parts store, the #2723 may be a little difficult to track down. Pep Boys Auto Parts is one store that stocks the #2723 bulb. Car dealers may be another source, since the #2723 bulb is used for the third brake light in many different makes.
  4. Reinstall the instrument panel and steering wheel by reversing the directions above, and test your lights. You should expect your panel to be at least 50% brighter than before.

If installing these new bulbs still doesn't make your instrument lights bright enough, you may want to bypass the dimmer switch. Some 308 owners have measured up to a 2 volt power loss through the dimmer switch, and bypassing the switch has produced much brighter instruments. Using the following procedure will render your dimmer switch inoperable, but most of us keep our dimmers at full power anyway and the procedure is simple to reverse if needed.

  1. Remove the instrument panel and steering wheel as outlined above.
  2. Unplug the wires connected to the dimmer switch (which is located next to the odometer reset button). The switch has one white wire and two yellow wires. The yellow wires are tied together with a single quick disconnect.
  3. Using the same gauge wire as the original wires, create a new bypass wire with an insulated male spade connector on each end. Connect this bypass wire to the female spade connectors white and yellow wires. Make sure your connections are insulated to avoid shorting out the circuit.
  4. Reinstall the instrument panel and steering wheel by reversing the directions above, and test your lights. The dimmer switch will no longer affect the brightness of the lights, and your lights should be visibly brighter.

Contributions to this FAQ by: Jeff Bootz, Vincent Pernice, Dave Handa, Henry Chin