Charging problem?

[EKjimmy]

G'day all,
I'm running an 85A bosch alternator in my EK with the grey motor. Up until now it's been starting first time every time, but a few days ago it seemed the battery was flat. Starter solenoid made the right sound, and when i jump started it off another car the alternator seemed to be making power.
After a little run, the car was starting normally again-even after sitting witht he radio on at the drive-ins. Stopped again today after filling up at the servo and had to get a jump off another car.
I'm just stumped as to what it could be-starter solenoid is obviously okay, battery was brand new late last year and still seems fine, alternator must be charging otherwise it'd need a jump every time.
Generator light isn't coming on except for when its supposed to when you turn on the ignition (but it does work)
Any ideas?

Jimmy

[Blacky]

Jimmy , grab a multimeter and test the voltage across the battery when the engine isnt running , then start the car and check it again - the voltage should be higher when the motor is running - about 13.6 Volts or thereabouts.
This will tell you if its charging or not.

[EKjimmy]

righto i'll try that cheers blacky

[EKjimmy]

update, got her running again after charging the battery for a bit. checked battery water levels, they're OK.
when running, battery charges to 14.35V both at idle and under revs-headlights don't dim or get brighter or anything, so i don't think it's teh regulator.
Battery was brand new mid last year and still seems fine.
While going through the service manual I found some troubleshooting stuff on the starter motor, including running a cable from battery +ve to the starter solenoid switch. When I did this, the car kicked over- so i thought this could be the problem, BUT when i started the car normally after it kicked over, everything seemed fine.
So I've pretty much ruled out regulator, alternator, battery and starter solenoid.....very strange to me.

Anyone have a clue?

Jimmy

[Blacky]

Check all the leads are tight - even the negative lead. I had a Landcruiser that wouldnt start when it was hot - pulled the leads off it , ran a tap down the threads and put them back on with new bolts and it never played up again

[Ken]

update, got her running again after charging the battery for a bit. checked battery water levels, they're OK.
when running, battery charges to 14.35V both at idle and under revs-headlights don't dim or get brighter or anything, so i don't think it's teh regulator.
Battery was brand new mid last year and still seems fine.
While going through the service manual I found some troubleshooting stuff on the starter motor, including running a cable from battery +ve to the starter solenoid switch. When I did this, the car kicked over- so i thought this could be the problem, BUT when i started the car normally after it kicked over, everything seemed fine.
So I've pretty much ruled out regulator, alternator, battery and starter solenoid.....very strange to me.

Anyone have a clue?

Jimmy

if all else on the + side tests out fine, its probably a poor earth, under intense load a poor earth will heat up and create resistance, therefore drop voltage and struggle

check the battery earth and the point where the body is earthed

good luck

[EKjimmy]

righto, cheers fellas