The OBC backlights in E30s burn out from time to time. Well, recently, it was my time! There are two bulbs, wired in series, which means that if one burns out, the other stops functioning as well. When this happens, the display goes dim (like when the ignition is turned off). The dealer charges a bundle to change the lights, and the printed circuit board with the lights costs $20. However, if you get two 6V lights from Radio Shack (part no. 272-1140), you can solder them right in.

First, you need to remove the OBC. In order to do this, I took out the radio and the passenger’s side console side panel. The panel is secured by several nuts and trim screws, none of which are difficult to remove. Once you have access to the backside of the OBC, remove the four philips screws that hold it to the console. This takes some dexterity, patience, and foul language. The OBC then removes to the front of the console. The light circuit board is the white thing on the right side – remove it with a pair of needle-nosed pliers. Once it is out, remove the white plastic from the circuit board. Use solder wick to remove the old lamps, and solder in the new ones, being careful not to create a short. I didn’t find it necessary to re-install the little white lamp supports for the new bulbs.

At this point, re-install the white plastic “reflector”. Insert the board back into the OBC, and check that the lights work! It wouldn’t be terribly fun to put it all back together and find that it doesn’t work. If it does, sew the whole dash back up. I only installed two of the corner screws to hold in the OBC (the rest had disappeared behind the dash). It holds perfectly well, and now I can see my display!

E30s tend to have problems with water entering the trunk.  There are several possible culprits in this case: a blocked sunroof drain tube, bad taillight gaskets, or a bad trunk gasket.  I’ve had experience with the latter two.

Taillight gaskets are fairly easy to replace.  Simply turn the two black knobs on the taillight assembley to unlock it, and pull it from the outer housing.  Then undo the nuts holding the outer housing to the body.  Pull the housing out, and replace the gasket.

A bad trunk gasket is also easy to replace, but a little trickier to diagnose.  I finally tracked it down after a rainstorm when my car had been sitting on a hill.  Rainwater was flowing down the channels on either side of the trunk, and pooling in the little triangular-shaped depressions on either side of the trunk (below the rear window).  This water was then flowing over the trunk gasket into the trunk.  A few bucks and a few minutes later, my trunk was water-tight again!

For driver’s schools, you need to give your car a good once-over to make sure that nothing is going to break on you at speed on the track. This includes changing oil and brake fluid, and checking the condition of all of your suspension and brake bits. Note that this list is not all-inclusive; please take the time to ensure your car is up to the rigors of a driver’s school before heading to the track!

Continue reading →

Although I replaced my brake pads and rotors recently, my brake lining warning light came on a while back. To track down this problem, you need to understand how the warning system works. Voltage is applied to a continuous loop of wire, which runs through the sensors in the driver’s side front pad and passenger side rear pad. If there is a break in the loop (such as when the brake pads are worn and the sensor’s contacts open), the idiot light illuminates. After checking my pads to ascertain that this was not the case, I started looking at the wiring harnesses on the body. In the front, the wires from the sensor had abraided against the caliper and split open; simple crimp connectors fixed that. However, the light was still on. I tracked the culprit to the rear wiring harness that wasn’t continuous. Replacements are available from your local BMW dealer, part number 61 12 1 367 674. I simply spliced the new harness into the old one upstream of the discontinuity. To make things easier in the future, I used bullet connectors for the splice, and wrapped the junction in waterproof electrical tape.