355 dash instrument light bulb type/no.?

Interesting. The numbers I listed came from CEC Industries, the maker of the 2721 and 2722 bulbs on Memotronic's website. I converted the MSCP values given to lumens using the 4pi conversion. The 2 different values are pretty close for the smaller bulbs but off more than I would have expected for the larger.

 

Out of ignorance, I did turn on my ignition 2 separate times while my cowl was out. Maybe I was just lucky but when I put everything back together, everything worked normally. Go figure?!

 

Here's an update on the dash and instrument lights.

I put the OEM incandescent bulbs with the OEM green socks back in my car, (3) 1.2W in the tach and (3) 2W in the speedo. The oil and water each had 1.2W with the OEM green socks and 2W clear for the idiot lights (these shine through red plastic built into the 2 gauges).

In a completely dark garage, the speedo was noticeably brighter than the tack and both the small gauges were about the same as the speedo. The difference didn't "jump" out at you but was definitely there. I have checked three different 355 instrument light groups and found all had the same 1.2W bulbs in the tach and 2.0 bulbs in the speedo. Since there is a noticeable difference in intensity, I'm at a loss as to why Ferrari appears to have deliberately done this. For me, I don't like the difference so I'm going to replace the tach 1.2W with 2.0W to make them the same.

I have not checked the lights in the 3 small gauges above the radio yet but expect them to be the same as the two in the cowl, 1.2W. If they turn out to be 2.0W, I will likely change them to 1.2 to match the others.

As to the HVAC control unit in the center console, I have replaced the 3 LED's with 3 clear OEM incandescent bulbs. Unlike the other instrument bulbs that can be pulled out of their sockets, these are permanently attached to theirs. There were no visible marks on them either so I couldn't tell what their wattage rating was. I did check the light intensity though at the same time as I did for the others. These lights shine through a new overlay from Dave Rocks (which by the way, in my opinion, is better than the one I had from Hill Engineering). In my car, the intensity here was less than the other console lights and the left hand side was not as bright as the right (don't know why...bulbs are the same and the plastic diffusers appear symmetrical). It was definitely dimmer than the other dash instrument lights too but I don't think it needs to match those. In my opinion, its a bit too dim. So, I am now in the process of trying to find 2W bulbs that will fit in an effort to brighten it up. Don't know if 2W is larger than what OEM is but they are cheap so I'm going to try some if I can find them that fit.

When I'm finished, I'll report back with the rest of my conclusions.

 

Here's my final update on the dash and console lights.

Instrument cowl lights:

1) Tachometer - Replaced the three (3) OEM 1.2W with three 2.0W. Reused the OEM green socks and black plastic bases. This now matches the speedometer light intensity and I like this much better. The bulbs came from Memotronics and are 2722 types. They come in packs of 10 at $4.99 each pack. These bulbs simply pull out of their bases for easy replacement.

2) Speedometer - Retained the three (3) OEM 2.0W type 2722 bulbs with their OEM green socks and red plastic bases.

3) Water Temperature and Oil Pressure Gauges - Retained the single 1.2W type 2721 bulb with its OEM green sock and black plastic base in both. Also retained the single OEM 1.2W type 2721 clear bulb and their black plastic bases for both gauge's idiot warning lights. If you need any of the 1.2W type 2721 bulbs, they are also available from Memotronics in packs of 10 at $3.99 each pack. These bulbs also just pull out of their bases for easy replacement.

4) Instrument Cowl Warning Lights - There are 20 warning lights around the cowl, 4 on each side and 12 across the bottom (including the 2 turn signals). Stock, these are all 2.0W type 2722 bulbs in red OEM bases.

Like all the other bulbs in my car, all but 4 of these had been replaced with LEDs. LEDs are polarity sensitive. If they are reversed in their sockets, they won't light up. You can't tell which way is which unless you mark them yourself. When my cowl was out, I inadvertently had rotated one of my turn signal LEDs the wrong way so the cowl had to come back out to fix it. Since most of these only light up when first started or are only used infrequently, I didn't see an advantage in LEDs here so I opted to replace them all with OEM 2.0W 2722 type incandescent bulbs in their OEM red plastic bases.

4) HVAC Console Control Unit - Replaced the three (3) clear OEM Neo-Wedge type T-1 1/4 (W rating unknown...estimate 1.2W) bulbs/black bases with larger T-1 1/2, 2.0W Neo-Wedge bulbs/grey bases. These bulbs are rated at 14 volts so operating them at 12 volts should only add to their 7,000 hours of rated life. I am very pleased with the result. They now match the rest of the console button light intensity exactly and all HVAC markings are now lit up uniformly. The bulbs I found are made by JKL and are type DNW1-EW87/GRA. Unusually they have a T-1 1/4 base with a T-1 1/2 bulb. The bulb is not only slightly larger in diameter but also 3 mm taller (still allows 6 mm clearance below the plastic light diffuser). The overall light distribution and intensity is now much better. The base matches the OEM base perfectly except I did squeeze the circuit board locking tabs a tiny bit. Although they could be snapped into place as is, they were a very tight fit and this made them easier to twist into place. These came from Mouser at $1.16 each bulb.

5) Three (3) Gauge Cluster (Clock, Gas and Oil Temperature) below the radio - I haven't taken these out yet because I am waiting to do it at the same time I replace the radio with a new OEM Sony unit (the radio has to come out to get at the gauges!?!?). These are now LEDs but I plan to replace them with OEM 1.2W type 2721 bulbs with OEM green socks just like the 2 in the main instrument cowl.

I hope this clears up what OEM bulbs go where and what I believe are better sizes in some of the places.

 

I need to make a small correction, add a caution and make 2 acknowledgements.

First, let me say thanks to both johnk and Daverocks for their help with this. John researched the bulbs and where to get them and Dave provided some bulb information to both of us. Thanks very much guys. This is what Fchat is all about.

The correction: The 2 clear idiot light bulbs in the water temperature and oil pressure gauges are not 1.2W. They are 2.0W. Everything else is correct.

The caution: Sometimes a bulb didn't make good electrical contact with its plastic base. Either the bulb wires were slightly out of alignment (easy to bend them back), the base internal electrical contacts were bent too far open (twisted them back with a small stiff wire hook 2" x 1/8") or, in a few cases, the bulb wires were too short and when the bulbs were seated all the way into a base, they lost contact (reversing or replacing the bulb fixed that). So, moral to the story, be careful to check each bulb in its socket before you install it to make certain its working correctly. Some may not be making proper contact.