Just cant figure it out...

[sidewayzisbest]

If the diode is bad in the alternator then the same thing can happen. The alternator turns into a really crappy motor when not being driven by the engine.

Is there anyway to check the diode in a alternator without pulling it apart?

 

[Daggar]

Is there anyway to check the diode in a alternator without pulling it apart?

Actually there is. You can have the charging system checked out at any dealership or a lot of times, autoparts stores will have a roll away machine and they can check it out for you. If you're handy with a multi-meter you can do it yourself by completely disconnecting the battery and alternator electrically from the car. Use the continuity tester to shoot through the diode on the alternator (or you can use the power lead from the alternator) and then to ground on the car. The continuity tester shoud only "beep" in one direction. Meaning: When you touch the leads to the power output terminal on the alternator you'll get a "beep" but when you reverse the leads you should get NO "beep". If you get continuity in both directions then the diode is bad. Sometimes you can just replace the diode... other times the whole alternator has to go (replcacing the alternator is usually easier).

 

[HISSIN50]

yep, normally replacing the alt is easier/more efficient, as said. a diode is just a one way valve (think check valve) if that helps you get this stuff.

good luck with testing - loose connections will create plenty of trouble.

 

[sidewayzisbest]

i dont have that tool =/

but if i go up to autozone and they check my alternator and battery and say its fine , do you think it could be that wire i made up?....but would that cuz it to drain from start up?

thanks for the help so far

 

[HISSIN50]

if it bench tests alright, i would look for poor/intermittant wiring connections.

 

[sidewayzisbest]

Well tomorow were going to try to hook up my friends epec real quick and datalog the battery and alternator but i got a feeling im going to have to buy that wiring kit anyways but think its something else too

 

[sidewayzisbest]

well update....couldn't hook up the epec just quite yet..but my battery cable the positive one fairly new (2-3 weeks) the connector looks a lil burnt.......what would cause that?