Many E30 owners have had their "Anti-lock" light come on on their dash at one time or another. Any time this light is on, the ABS isn't functioning, and more times than not, this is caused by a blown fuse element in the ABS relay. This fuse has a nasty habit of blowing if the car is ever jumpstarted backwards (meaning with one car's positive terminal connected to the other car's negative, and vise versa). To make matters worse, BMW used a red battery cable for the battery's negative terminal, and a black cable for the positive one, so a backward jumpstart is more common than you'd think!

If you know you jumpstarted your car backwards right before the light started coming on, there is a 99.9% chance that the relay is your problem. If you don't remember, there's still a chance. The expensive solution is to buy and plug in a new ABS relay. I beleive they're availiable at Bavarian Autosport (www.bavauto.com). Not only is this expensive, but if you ever jump start the car backwards again, you'll have to keep buying them. If you do buy a new one, keep the old one just in case you ever want to fix it, because the new ones with the plastic case, I believe, aren't repairable.

A better, and much cheaper solution, is to fix the relay you've got. You'll need a soldering iron/gun. If you don't have one, you can get one for $5 at Radio Shack. Don't worry if you've never done soldering before; it's really easy.

First remove the relay. Remover the lower dash cover, which is secured by three black plastic "screws", which are rotated a quarter turn for removal. The relay is located above the ABS computer, the metal box to the left side of the steering column under the dash with the long fat white connector on the front of it. The relay is the only thing clipped to the top of the computer. Rotate is one way, and then wiggle it to get it out. The relay itself is a metal box about the size of two 9V batteries. Unplug the connector from the bottom of the relay, and take it out of the car.

To get the metal casing off of the relay, take some pliers and bend up the tabs on the bottom that hold it to the plastic bottom. Once the tabs are out of the way, gently pull out the relay, noting it's orientation in the casing. Now look at it. Near the base of it, there should be a fuse element running from a small pole to the copper on the relay. In the picture, it runs between where the two green wires are soldered on. If the fuse looks clean and silver, and it's one piece, put the relay back together; you must have another problem with your ABS. If there's any doubt about the condition of the fuse, go ahead and fix it.

You'll need a few things before going any further, all of which are availiable at your friendly local Radio Shack. First, get an 8 amp 1 1/4 by 1/4 inch glass fuse and a fuse holder. If you wish, you can get a blade type automotive fuse, but many times they aren't availiable in 8 amp varieties. Don't substitute another fuse rating. You'll also need some wire. I used 22 gauge multistrand copper wire. You can use whatever you want. Of course you'll need a soldering gun and solder, as well as electrical tape.

Heat up the solder holding in the old fuse element, and remove the charred bits of old fuse. Then solder on two pieces of wire, one to each place the old fuse was connected. Now cut the wire to about 4 inches, and solder the other ends of the wires to the two terminals on the fuse holder. Tape the terminals on the fuse holder tightly with electrical tape (you must do this, or else this thing will start to spark as soon as you put it back in the car). Insert an 8 amp fuse into the fuse holder.

Now you'll need to cut a small hole in the casing to allow the wires to poke out. I used wire cutters, as the case is soft aluminum; use whatever works. Cut the hole just big enough for both wires to stick out. Once you've done that, replace the casing and bend the tabs back down so that it doesn't come off again.

You're done! Clip the relay back on top of the ABS box, and crank up the engine and see if the light goes out. If it doesn't, you either did something wrong, or you have another problem with your ABS. If it does go out, celebrate! Wait for a rainy day and go try it out!

The beauty of this fix is that it not only fixes the fuse, but converts the relay to a replaceable fuse setup, so if it ever blows again, you just pop in a new fuse. You'll never have to open the relay again.