alternator

[Hearts88]

Hi everyone.
I have a 1987 Cutlass Supreme with the 3.8L. Recently the car has been charging low. So I checked the belt tension, and it seemed fine.
so I did the old test, I pulled the battery terminal while the car was running and it died immediatly. That I fiugred meant the Alt was not charging. I took it to Canadian Tire and had it tested. They told me it was good.

Shrugged my shoulders and put it back in the car. Re-adjusted the belt and the car was running OK for a few weeks. Was still charging a bit low but wasn't really a problem.

Last week the car died as I got it into the driveway. Tried to start it and the battery was dead. So I charged the battery, started the car and again pulled the battery cable. Right away the car died. So I out a tester on it while it was running. The tester is only showing an 11volt charge from the ALT. What should it be at? about14volt?

<rant>Now when I had it bench tested from Crappy Tire they said it was good. Not it is charging at xxvolts. So what the heck is the fine line that thier machine says it is good and no good? 10 volts? 'cos I'd be on the border line then.

Anyway, the ALT is charging at 11volts... too low right? Should I go get a new ALT? Or could it be something else?
The Battery terminals are clean and good. The Alt termial and connection is all clean and good. There is no power nothing in the car, just the basics... Fan, lights, wipers etc.

If anyone can help out.... please and thanks!
Hearts88

[maxwedge]

Should be at least 14v. See what it is with the headlites on, anyway it looks like it's bad. BTW, do not test an alt. by disconnecting the battery.

[Hearts88]

Originally Posted by maxwedge

Should be at least 14v. See what it is with the headlites on, anyway it looks like it's bad. BTW, do not test an alt. by disconnecting the battery.

Why not test by disconnecting the battery?
My understanding has always been that if you disconnect the battery the car should still run and continue to run the electrical without the battery. Or is it a possiblity of shorting something?

Hearts88