I was installing my battery back, i connected the positive and negative, then to turned on the car, then while i was going to screw the bar down that holds the battery i hit the the positive like 2 times and it made a spark, then i drove and my battery light came on then it started to die, i went to autozone got a recharge then while i was driving a couple hours later it did the same thing. now when i drive the battery light goes off but when i stop it comes back on. could anybody help me with this

 

You may have done damage to the (I wanna call it a regulator??) The part that actually sends recharging power to the battery. The Diodes or Rectifier could also have gone "Hiroshima".

Take joo alternator off...and go "Get in the Zone."...have those guys test it. If its good, then the problem may be deeper...and the depths of a Lexus Electrical system is not where you want to be.

 

blown main fuse?

 

you can test the alternator still on the car, so long as the battery is in good shape... a good tester will show bad diodes (high AC voltage), low output (amps), or bad regulator (incorrect voltage)

 

lol what are the diodes and the rectifier?

 

What he said

 

ok is this true, my father said i can check the alternator by unpluging one of the wires and if it cuts rite off then the alternator is bad, is that is this true, if so im about to try it

 

I've taken my alternator off and taken it into Advance Auto Parts a couple of times to get it checked out.

 

is it hard to take off the alternator, this would be my first time doing this, and were is that regulater at to?

 

The diodes and regulator are all inside the alternator. To remove the alternator from an sc300 is fairly easy, here is a link: https://www.clublexus.com/forums/sho...ght=alternator

Not sure how hard it is on an sc400 though.

 

no, its not hard, but it wouldn't be a bad idea to check everything else first...

from what you described, it sounds like you popped a main fuse... did you check those?

 

yea i checked all the fuses in the kick panel and the engine bay fuse box and everything is good

 

i fixed it , it was the alternator, man it took me like an hour to get it out but like 5 min to get it back on