The BMW light control module, commonly known as the LCM, lamp control module, or light check module, is an extremely common part that fails on the BMW E38 and E39. What is it, how does it work, and why does it fail? Once upon a time, a light switch in a car simply completed a circuit between the...

Power windows on the E53 BMW X5 have became known for failing with age, often leaving the window jammed in the fully down position. Earlier BMWs tended to use a 'scissor lift' style window regulator, but around the time of the X5 BMW started moving to a cable & pulley system. There are...

The most common reason for a car failing to start is simply that the battery cannot provide enough power to turn the starter motor. While the easy repair seems like a battery replacement, there's a chance the problem is elsewhere within the battery and electrical charging system. Before you go...

Drive belt tensioners are a sometimes overlooked maintenance item, and if your car has 100K-200K miles on the clock then it could need replacement. As the name suggests the job of the tensioner is to keep tension on the drive belts on the front of the engine that link components suggest as AC...

Not having air blowing in the cabin, either from AC or heating, is usually electrical in nature and can be quickly narrowed down to either fuses, the control module, or the blower motor. Fuses are easy to check of course, but control modules can be tougher as they are somewhat of a black box. You...

The CV joint boot on the front left of the E53 BMW X5 is notorious for premature failure - quite often it is found to have failed whilst the other 3 corners are near pristine! When the boot tears, grease inside the joint can escape allowing dirt and grit in. When this happens, failure of the...

Some Mercedes models like the W220 S-Class and E210 E-Class include a heated washer fluid reservoir in addition to heated spray nozzles.  From the parts diagram below you can see it works by recirculating engine coolant throughout a pipe loop within the reservoir. This is great for keeping the...

Seats are often the first thing you see when getting in a car, and old worn/dirty seats make a terrible impression when buying or selling. On the other hand, great seats can really lift an interior and increase the value if you're trying to make it stand out. The original seats in my 1993 BMW...

I recently wrote about checking driveline mounts and flex joints and the problems they can cause on a BMW, often starting as vibrations. This time let's look at the practicalities of swapping them out on the Mercedes W220 S-Class chassis.  The procedure for E-Class and R-Class models is very...

Cold weather can lead to strange problems with cars - in my case the gas pedal simply stopped working.  In the late 90's many BMW and Mercedes models moved to electronic drive-by-wire gas pedals and throttles.  Worthy of an honorable mention is the E32 BMW 750iL, which used drive-by-wire way back...