Help, car keeps dieing

67Dart273 said

The trouble with so called "testers" is that

1--They only show if something is bad, not good, and are only reliable if they are "honest" and the operator knows what he or she is doing

2--No typical parts store alternator tester can test an alternator under full output load. This means there is no way of knowing whether your 40, 50, 60A unit can actually output it's full rating.

In other words, these testers are fine as far as they go. They are not absolute

Click to expand...

I understand they don't load the alternator to test for full output but his description makes it sound like it's not charging whatsoever. Agreed that a tester is only as good as the operator but I have yet to run into a case where they told me something was bad or good when it wasn't. Had a couple times where they couldn't get it to test (problem with the tester) but they told me. I suppose it's possible some unscrupulous person could lie about the outcome. So far I haven't ran into that.

Since you don't trust having them tested what's your method for determining what the problem is?

70 would be a dual field circuit, correct? If that's the case I think to test the alternator for output one of the field wires needs to be ran to B+ and the other to ground. If it charges "hotwired" that tells you the alternator is good and the problem is elsewhere. Is that correct?