Thursday, June 26, 2008


Well, if you listen to so many back yard mechanics, and pull off that battery cable, then you , like them are suffering from oxygen depravation. You know, the sphynxter is too tight around the neck cutting off circulation to the brain.
Yeah, if your made of money and use it for toilet paper go ahead. Yeah, the engine will more than likely die, but not because the alternator is bad. Probably because you just spiked the system and fried most of you engines sensitive, low voltage sensors that feed info to the computer. And you still don,t know if the alternator is bad or good.
Years ago before the advent of computer controlled emmissions systems, and alternators, there were generators keeping the system charged and running. Pulling off the (+) positive cable to the battery was a viable test to see if the generator was working. The engine would indeed stay running if it were. Even prior to th mid eighties you could even test an alternator this way, but not after, say '86, when things started getting deep into the computer controlled crap. And after 1990, definetly don't do it. EVER.
All you need to test an alternator is a cheap test light or VOM. With the engine running clip the negative lead of the test light to the negative terminal, and stick the postive terminal with the test light and the light will light. Have someone turn on the headlights. If the test light dims and stays dim, the alternator is probably not putting out. If the light doesn't dim, but usually it will brighten a little, it's probably putting out. With a volt-ohm meter, neg lead to neg terminal, and pos lead to pos terminal. The voltage dial on DC 15volts, the reading should be 12 to 14+ volts. Turn on headlights. If voltage drops and stays below 12volts, then the alt is probably not putting out. If the voltage increases toover 12, then it probably is. If you end up having to ever replace the alternator, please have the battery checked also. Batterys hate AC voltage, and if the rectifier goes out of your alt, then guess what kind of voltage the battery is getting? And if you have a bad cell or two, the you'll work the new alt to death trying to keep it charged.
Oh yeah, starters hate bad batterys. Kills 'em almost as quick as over-cranking.


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