Every so often a story comes along that makes you wonder What were they thinking. This story at CNN discusses a recall by Ford of almost 4 million vehicles that are prone to burning themselves up. The article describes the problem -- it's a switch, with always-on unfused 12V power that's mounted in the brake fluid reservoir. The problem is that there's a barrier that's supposed to keep the fluid out of the switch, but (what a surprise) it occasionally fails, lets fluid into the switch, creates a high-current situation that eventually catches on fire. Now, the view from the sidelines makes me wonder why in hell they'd a) mount the switch near flammable liquid, b) not limit the current to it, and c) keep it powered 24/7. I mean, how freaking stupid is that? The switch is used for the cruise control and reports brake state. Wouldn't it have been smarter to put it on, say, THE BRAKE PEDAL?
Now I've owned a number of BMWs. E28 535i, E30 325iX, E34 535i, E39 540i, and an E36/7 M-Roadster. I do an above-average amount of maintenance and repair myself. I have an engineering degree and am comfortable and informed working around mechanical, electrical, and electronic systems. In all my years of owning and working on mine, and friends' BMWs I have NEVER seen anything as stupidly designed as Ford's cruise control switch in any of these BMWs.
So here's my question: aside from the afterthought pollen filter in the E34s, have any of you ever run across anything in your BMWs that a low-IQ chimpanzee could have designed better? In any car you've had?
I actually worked on that case in my old job of forensic engineering. I was supposed to try to make it do it in a lab to show that the ignition could be reproduced, but I left to go back to school before we finished getting it set up.
The tricky part about it is that brake fluid only conducts electricity when its dirty and has water in it, so for a long time, people had a hard time reproducing the results in a lab, and that kept the blame off of Ford. The sucky part is that when Ford was found reponsible, they would pay for the cars that burned, but not the houses that burned to the ground around the car.....nice.
Now, it may have been a bad design, but Ford wasn't neglidgent. They had a recall for that brake switch for years before cars started burning up.
93 525i / 01 330Ci / 98 Camry / 91 Volvo 240 / 99 Jeep GC