Alternator

C

cars56

Senior Member
Hi All
Any way of confirming (test) that the alternator (diodes) are draining the battery with the engine off and sitting for a couple of days?
 
take either battery cable off the battery. take a 12 volt test light connect one end to the battery post you removed the cable and the other end to the cable you removed. if it lites you have a draw. if so remove the battery wire off the alternator and see if the draw goes away.
 
There may be too much resistance in the circuit to light up the test light. An ammeter would tell you if you have a small leakage current. By that I mean a test instrument, not the dash ammeter.
 
cars56 said:
Hi All
Any way of confirming (test) that the alternator (diodes) are draining the battery with the engine off and sitting for a couple of days?
Click to expand...

just pull one wire from the alt connection car off...retouch wire..if spark not good:eek: !
 
Get a cheap meter from some place like Hardor Freight to check the current. A light bulb might not light is the currect is real low, same with a spark.
 
You've got a built in tester in the car. Simply disconnect the alternator and leave it sit for a few days. Battery stays up, problem is in the alt. Still goes down, look somewhere else.
 
If you take alt apart, there should be continuity between bottom prong and all 3 top prongs of the diode-triode... If one is out you will have slow drain on battery....
 
Last edited:
You must log in or register to reply here.
Back
Top