Righty Tighty, Lefty Loosey

Today I’d like to share some wisdom about, well wisdom.  It’s that magical time of year again when the temperatures are warm, pollen is in the air (and your eyes), and you’re anxious to get your summer toys out of hibernation.  It's also when batteries are weak, tires are low on air, and that trailer of yours definitely needs its bearings repacked with grease.

A few years ago I fell down the rabbit hole one night and found the greatest piece of wisdom I’ve ever come across.  “Righty tighty, lefty loosey is only great advice if you know when it's not”.  I had it tattooed to the inside of my eyelids the next morning.  All too often the cars we car nuts adore fall into a category where we you need to worry about more than just left hand threaded lug nuts.

Take my 1991 BMW 325iX sedan for example.  Despite my best trickle charging efforts this winter, its battery finally gave up the ghost and needed to be replaced.  If you know it how to jump start a car and know it’s located in the truck (in my case here), you’re probably qualified to do it yourself.  But if you don’t pause and think for a second while you do it on an e30 BMW, you’re also qualified to fry some wiring.  At least if you're thinking "red is positive, black is negative"...The electrical equivalent of "righty tighty, lefty loosey".  

The cable on the left is black.  The cable on the right looks red, right?  Well in a dark garage, maybe.  Turn on your flashlight and you'll see that the cable on the right bolts directly to the body of the car.  Huh?  What's going on here?

If you've ever wired socket in your house (properly), you can see where BMW is going here.  The black cable is the "hot" cable while the faded brownish/red one is serving as the "earth".  Luckily, the enginerds in Munich decided to equip e30's with batteries that have recessed terminals.  This makes it harder to install the battery backwards, but it's possible to do.  I've almost done it myself!  With so many e30's bastardized over the years I know many have the incorrect battery installed in them.  Quickly replacing the incorrect battery with the correct one with different terminal orientation than your used to can ruin your day.  

Here's a non-exhaustive list of things to check twice before you rush and really feel like an idiot:

Left handed lug nuts were common on the driver's side of cars through the 50's and 60's.  Chrysler was the last hold out.  Most anything built after 1975 has right hand threads all the way around.  This is a case of "Lefty Tighty, Righty Loosey".  

British cars are infamous for their electrical systems.  Many had an electrical system where the positive terminal acts as the ground.  To the uninitiated this is a hard concept to wrap your head around.  Muddying the waters is the fact that many old British cars have had their electrical systems converted to negative ground.  Here's a video explaining how to identify what your British car is running.  Just don't email me if it catches fire.

6 volt electrical systems are out there.  Air cooled Volkswagens, 50's Chevy Bel Airs, Jaguar XK 120's, MG T-Series, and Triumph TR2's & TR3's are among the most common, but some have been converted.  Most of these 6 volt cars have a "Group 1" battery with easy to open caps and terminals positioned diagonally to each other.  So be careful if you need a jump start!

It's very hard to put diesel fuel in your gasoline powered car.  This is because diesel pumps are a bit larger and won't fit in a gas car's filler hole.  But this also makes it very easy to put gasoline in your diesel car.  The powers that be think you're smart enough to remember your W123 Mercedes runs on diesel, but some people space out .  I had many, many customers mis-fuel their diesel cars while I was working as a service advisor.  I made tons of money in commission while they paid tons of money to fix their mistake.  Don't be that person.

Think twice before you do that seemingly simple task to your car this spring.