[JWT4700]

Can someone explain this a little more?
I just watched this vid on how to test alternator and gave it a shot. It's tested ok as far as only getting a reading one direction, but my reading came back at about 350, not the specified 500-800. What exactly does that mean?

I'm still chasing a battery drain issue as well as a bsd issue and wondering if this just might be it?


Anyway here is the video

[mksher]

have you found anything else out? I'm having a similar issue. my alternator tests in the low 400s but the car dies after sitting for 2 days. what BSD issue are you having? I have a code for "BSD error water pump missing" and "BSD oil sensor missing" but both seem to be fully functional

[TunafishE93]

The diode test you will get different readings with different meters. Its hard to diagnose a bad diode in the way in the video since they are all getting tested together. The main thing in the video is you are not getting readings both ways.

Then you would have to test each diode individually and compare the readings to each other. If you have a bad one it will show up as a different reading than the rest. Testing them as a group wont always show if there is a leaking diode.

[Ea$y]

Where are the diodes, are they in the voltage regulator or in the alt?

[e90yyc]

Originally Posted by Ea$y

Where are the diodes, are they in the voltage regulator or in the alt?

You know those spikes they use at the entrance to some parking lots to prevent cars from going the wrong way? A diode exists for a similar purpose: to prevent electrical current from flowing in the wrong direction.

They are not in the voltage regulator; they are in the diode bridge at the backside of the alternator.

[Ea$y]

Is there a way to replace the diodes without replacing the alt? From a practical stand point.

[Brian86]

It's not really practical to replace them.

It's a very compact arrangement with the diodes more-or-less integrated into the stator windings and soldered to cast plates at the on the back side of the alternator.

Not impossible, but not practical.

[je92iek]

Could it still be a diode problem even if i just replaced my alternator ?

[lordnikon]

Originally Posted by je92iek

Could it still be a diode problem even if i just replaced my alternator ?

Is it a new alternator?

[je92iek]

Originally Posted by lordnikon

Is it a new alternator?

Yes

[lordnikon]

Originally Posted by je92iek

Yes

It shouldn't because I did the same and I didn't get anymore batt drainage. A simple test can be done like here: