First off, i'm decently skilled when it comes to automobiles, but i'm just having some problems. My 90 mustang has a charging problem. It runs like the alternator isn't working. The battery drains as i drive it and i get no charge indication on my voltmeter. The alternator is new, and i have had it checked and the auto parts store says it's good. I checked the wiring to and from and all around according to the wiring diagrams and it checked fine as far as continuity goes. When i run the car i checked the voltages coming off the windings of the alternator and i'm only getting like 11.8 v. Also, my 90 has a lot of vibration when revving up to 3000 rpms or so. Would it be more likely that it is my flywheel or my driveshaft, or could it be my ujoints on my driveshaft. Any help or advice would be appreciated. also, i would like to know if there are any common places that oil likes to leak. I have some oil leaking from the back of the engine and i'm not sure if it's the valve covers or the head gaskets, would i see a lot more problems if oil was leaking from the heads other than just leaking oil. I"m not overheating and dont have coolant in the oil.

 

does it vibrate at 3000 rpms in neutral or drive?

oil leaking from the back of the engine could be a valve cover gasket or the rear main seal. check the valve cover gaskets first. they are a lot easier to get to.

have you checked your battery? maybe the alternator is fine but your battery isn't accepting a charge.

good luck.