ever since i install the HID controller (dont know if its the reason), my car is having a hard time starting up. i first thought it was my old spark plugs so i change it. still the same problem after the change. check the battery and it seem almost fine after a drive. but once its park for awhile the battery checking light that is on the battery goes clear. so im thinking that 1) the alternator is bad 2)my HID controller is mess up (dont know how but, when i install it, i had to guess a few wires since it only had 5 wires instead of 6 and 2 color wasnt mention in the installation so i just randomly tap into wires to see if it work). so back to the question, how do you do a alternator test?

also while i did the spark plug change, i notice that there were oil on the spark plug thread, spark plug wire where it seals the chamber, and a few wet spot on the valve cover. does this mean i have a mess up gasket?

 

Start with the battery first. Get it load tested at your nearest Autozone or Kragen. Next, load test your alternator to see if you're putting enough voltage out. That should give you some idea on what to work on.