I love gauges on cars – knowing what’s going on with your car (as long as you scan your gauges regularly) can save you a lot of hassle by catching problems early. For example, coolant and oil leaks.
Since I wanted to run a working three-gauge cluster, I ran a silicone vacuum line into the passenger compartment (for a boost/vacuum gauge), and installed a 5-bar oil pressure sender from E-Gauges to run to the OEM 240 Turbo 5-bar oil pressure gauge. I had to sand a tiny bit of the engine block (just using a coarse sandpaper) to get this sender to fit – it’s a tight squeeze.
I then ordered LED bulbs from superbrightLEDs.com. For the gauges and three center console bulbs, I used about ten model 74 xHP3, the brightest #74 that they currently sell.
For the dash switches, I didn’t need something as bright, so I got about ten of the single-LED model 74 xHP.
For the two dome lights (in a sedan, one dome light and one trunk light), I recommend these 9-LED festoon bulbs 4410-x9.
For the instrument cluster, I ordered two WLED-x5, the brightest #194 that they currently sell. (These didn’t end up being bright enough, and I later replaced the two main cluster lights with these WLED-xHP9-T bulbs, which I had to file down in a similar manner as described below).
Another option, instead of ordering from superbrightLEDs.com, is to get this kit from turbobricks member David Samuels (login required to view link). However, you will still have to file down the bulbs if you have a 1989-93 cluster, as shown below.
So, when I took my cluster out, I found that it didn’t use #194 bulbs like the older 240s (1981-88). Instead, the 1989-93 clusters use a smaller halogen bulb. This was something of a unexpected hassle, but I figured out a workaround.
Instead of just using the normal bulb holders for the main cluster bulbs (right two bulbs in the picture below), I had these smaller bulbs with a red base. To make the LED bulbs work, I had to forcibly remove the bulb from its fixed socket (wear face and eye protection, these bulbs are pressurized and will explode if cracked). Once removed, I had to file down the LED bulb (shown at left) just enough to barely fit in the stock bulb holder. Be cautious and don’t file too much or the bulb will be useless.
Because the LED bulb is bigger than the hole in the cluster, I had to take the cluster apart to mount the bulbs, putting them through the “front” side, and then putting the base on the back and tightening them down.
But, the end result is pretty nice. The cluster wasn’t as bright as I would like however, so I kept looking for better options, eventually settling on these WLED-xHP9-T bulbs. This isn’t the fault of the LED manufacturer, it’s really just an issue with the design of the cluster that relies on reflecting light from the back of the cluster. The brightness is about normal, and I was hoping for something brighter than the stock level.
The smaller #74 bulbs go into the 52mm gauges without issue, and also work throughout the dashboard for the center console illumination.