Yesterday I finally got a chance to tackle the battery discharge problem in Jill's 560 SL. I'd already convinced myself it wasn't an alternator charging prohblem. (I've been putting the car on charge most nights for months now.) I suspected one of the two alarms, or the stereo to be at fault. (Though it could be almost anything, including the clock, radio antenna, or dome light system.) I pulled apart the main power supply terminal under the hood and determined that there was no parasitic load except through the main feed wires to the fuse box. When I disconnected the keyless entry/alarm system and powered up the car it drew some 200 mA once things settled down. That's fairly hefty, over time. When I dug up the fob so I could reconnect the keyless entry/alarm and shut it up I found that it only seems to draw 10-20 mA itself: not so bad. Removing the faceplate of the stereo did nothing to change the draw. I removed the floor panel, but the factory alarm wasn't under there so I couldn't disconnect it. I mis-remembered, it's behind the glove box according to the ETM. (The lamp-out warning module is what's under the floor panel.) I ran out of time to continue chasing that morning, however.
Jill also reports that the headlights spontaneously go out sometimes. That's not good, and it keeps her from wanting to drive the car. Combination switch? I've seen that before, though usually only when applying a turn signal. Today I proved it's not the stereo (removed), or the antenna (unplugged). But it's on Fuse 12. If the schematic can be believed that indicates the antenna, trunk light, alarm system, warning module, courtesy lamps, diagnostic socket, hazard signals, or clock. I disconnected the alarm, that's not it. I pulled the dome light timer relay, that's not it either. I checked the visor lights, it doesn't seem to be them. (Current draw when either was opened was the same, 950 mA, and together it was about 1600 mA. That indicates that neither switch was leaking.) I pulled the door switches, no change. It's not the warning module. (Getting to that was fun.) It's not the hazard switch. All that's left is the clock, which is difficult to get to. So I pulled the airbag, steering wheel, and instrument cluster. It's not the clock! WTF? Supposedly I've gone through everything on Fuse 12, yet I've found no culprits. The car still draws 200-350 mA through the fuse. Damn, either somebody added something (cell phone?) or the schematic's wrong, or there's a pinched wire. The next step is to pull the fuse box itself and check the individual wires feeding off of it. That's a drag. So I pulled the fuse block. There are two ring terminals screwed to #12: one a clump of small reds with a red/yellow in it, and another clump of small reds with a red/white in it. The culprit is in the red/white clump, though I ran out of time to chase it further than that. The red/white wire itself goes to the diagnostic socket, and nothing's plugged into it. The car looks a right mess. -- Jim _______________________________________ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
