Here is the scenario...

I've got an 86 740 gle n/a with an m46. Several things have been getting worse/ happening recently as I approach the momentous mark of 200k. I'll go from most serious to just annoying.

First, 2 days ago the indicator lights in the instrument cluster that go on when you start the car didn't go off immediately. They stayed on dimly for a minute while i backed down the driveway and turned off as i was going down the street.

It happened again today. So, I figure maybe a bad ground or a short or something... I'll dig into months from now, cause i'm busy with school and stuff.

Tonight my mom tries to start the car and it's like the battery is mostly dead cause the starter will try to go, but can't turn the car over. She pushed it and we jumped started it. It ran fine for the few seconds i had it going except the instruments were jumpy like the tach would jump around. I disconnect the battery because I think it could be a short.

3 hours later I come home, hook up the battery and my mom push starts it. I pull it around to fix some wires that were all corroded going to the alternator thinking that could be the source of a major short. Then, we push start it again. This time the tach doesn't work at all. I want to charge the battery, so I take it for a spin. Several things occured: turn signal indicators would blink quickly, when i'd brake i would hear a relay clicking fast (like it's not able to stay closed because it's not getting enough power), if i'd turn my brights on i'd lose power, the speedometer reads too low (i was going maybe 50 and it read about 35), and eventually (and this episode lasted about 7 minutes) i couldn't go without turning off all power consuming things like lights. On a side note, there was a couple in my neighborhood who saw me and waved and pretty much jumped up in the air a few times. I bet they thought i was a high teenager coming home from smoking (which i don't ever do).

All I can think of is either the alternator is bad, or I just need to charge the battery up- which will be finished in the morning. Where do i test the alternator with a mulitmeter, and how much should it output at idle? Somewhere between 10 and 55 amps I'd say. Also, when I was gonna charge the battery, the charger says to connect the ground wire to a part of the chassis. The charger wouldn't charge unless i put the connector directly onto the cable that goes onto the battery. Even if i connected to the part where the ground cable goes directly onto the chassis by the engine it wouldn't work. I suspect maybe the ground connection there is rusted... I'll clean that too.

Second... I installed a used tranny... The tranny has always made a bad bearing kinda noise. Now I'm getting a loud continuous boom noise that resonates real well in the interior under load. I'm suspecting center bearing or u-joint, just from things i've read and the mechanic's who checked out the car for me said there was some u-joint and center bearing wear. How do I diagnose this problem? I don't know what a bad u-joint or center bearing look like. How much are new ones?

Sorry about the really long post. I thought the most details possible would be best for figuring out what's wrong. Any suggestions so I can make it to the 200k mile mark?

Thanks,

Nathan