This is true. Basically what he's saying is the test-light procedure will show a pretty big load but you CAN have a load above the standard (what's considered normal) less than or equal to 500mv draw that still wouldn't light a test light. The question at that point would be if it won't light a test light, is the draw large enough to worry about? Unfortunately, that would depend on the draw, how long the car sits, and the condition of the battery.ewill3rd said:Step 1: Have battery charged and tested at a competent shop.
Step 2: Take car to shop and have them check for a "parasitic load".
The method described in the last post used to work back in the 60's but with the advent of computer controls and digital clocks it rarely actually works.
I am not saying it can't work but it might be misleading in a fuel injected car with lots of electronics.
A digital meter should be used to check for a draw to see what is pulling your battery down, and yes, usually you pull fuses until the draw goes away and then start tracing that circuit.
Aftermarket stuff is a big source of parasitic drains. Be careful about plug in accessories, like phone chargers or other electronic equipment.
If it goes dead overnight it should be fairly easy to find.
You just made me realize that I was quoting the wrong figures here. I said mV but I meant mA, sorry. But as I recall, the proper figure was 500mA not 50mA. I could be wrong but I seem to recall half an amp was the cut-off. :hmm:ewill3rd said:Anything over 50 mA I consider to be a problem.
The spec on most cars is well below 30 mA.