The fuse for the power windows in my 240 wagon blew. I was in a neighborhood that wasn't to great with expensive equipment in the car, so I jumped the fuse using a nickel in order to roll the windows up. I'm not sure how it happened, perhaps I hit the wrong fuse initially, but the fuse that controls the clock/radio/power door locks also blew. In addition, the beeping sound that occurs when the door is open and the keys are in the ignition started going off. It beeps this way for the entire time that I am driving (from the moment the keys are placed into the ignition until when they are removed). I tried to replace the fuse, but the new one blew as soon as it made contact. I am told that this means that I have a short. Would this be due to poor grounding (melted wire) or could it also be due to a blown trace on a circuit board? How should one begin to trouble-shoot this? I have very limited electrical experience, but also a very limited budget.

You have two fuses on your car for the power windows. Number 10 and number 12. Check number 12, since if this one blows it also gives you the irritating ding, ding, ding. If the power window fuse blows again, try turning off your air conditioner. See if this keeps it from blowing again. As far as the other fuse; I'm thinking...I have no idea. I suspect that a nickel will support much more current than an 8 amp fuse. I suspect you had the key out of the ignition, and that you had the driver's door open when you were putting in your five cents, therefore I'd opt for the problem being somewhere in the circuit for the courtesy light. The brown wire on the 2nd connector on fuse #10 supplies the power feed for fuses 7-10. A spike, hopefully, didn't take out much. The things I would check first would be the overhead light, and the relay for the delayed courtesy light. Tiny silver cylinder under the knee bolster with four wires going to it. I guess try these things...and then let us know.

I don't remember off hand what else is on that circuit, but two things real likely for you to look at:

1) radio wiring behind the head unit. Especially with aftermarket installations, the wiring can get into the windshield wiper mechanism which is RIGHT behind it. This will sever wires like a shear, and short out the power wires. Pull off the top blanking panel next to the radio, and two screws behind there let you remove the whole radio. There are no screws on the right of the radio. Inspect this wiring and tape any bare wires. If it's cut, you'll have to repair it.

2) The dome light could short against the roof. These pry out pretty easily. A wire could have come off a terminal and hit the roof metal or be touching the black ground wire on the light circuit. Reattach a loose wire or tape it to prevent things from touching.

3) Has any other work been done on the car recently? Back up to the most recent job and look for any crunched, pinched, or cut wiring near that... you've definitely got a short connecting some wire right to ground -i.e. the body of the car.
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Rob Bareiss, New London CT ::: '87 244DL/M47- 229K, 88 744GLE- 218K, 82 245T-181K Also responsible for the care and feeding of: 88 745GLE, 231K, 87 244DL, 239K, 88 245DL, 246K