Sr20det runs fine, dies without battery, alternator bad? how can i test? - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

sepulchral · 08-11-2006, 05:56 PM

title says it all..

how can i test if alternator is bad?

bongnak · 08-11-2006, 08:07 PM

how do u test it?
you just did by telling us that it dies without the battery
when i test my altenators i usually just unhook the batt while the car is idleing and if it turns off then its a bad alty.

krustindumm · 08-12-2006, 12:19 AM

Disconnecting the battery while its running could cause electrical damage, especially on a bad alternator.

Use a DVOM and measure AC volatge between the alternator terminal and housing. More than .5V and its probably shot.

08-11-2006, 05:56 PM	#1
sepulchral BANNED Join Date: Mar 2004 Location: Midlothian. VA Posts: 2,050 Trader Rating: (0) Feedback Score: 0 reviews	Sr20det runs fine, dies without battery, alternator bad? how can i test? title says it all.. how can i test if alternator is bad?

08-11-2006, 08:07 PM	#2
bongnak Zilvia Junkie Join Date: Jan 2005 Location: So-Cal Age: 41 Posts: 337 Trader Rating: (3) Feedback Score: 3 reviews	how do u test it? you just did by telling us that it dies without the battery when i test my altenators i usually just unhook the batt while the car is idleing and if it turns off then its a bad alty. __________________ Zzzz

08-12-2006, 12:19 AM	#3
krustindumm Zilvia Junkie Join Date: Dec 2004 Location: Iowa Age: 40 Posts: 473 Trader Rating: (0) Feedback Score: 0 reviews	Disconnecting the battery while its running could cause electrical damage, especially on a bad alternator. Use a DVOM and measure AC volatge between the alternator terminal and housing. More than .5V and its probably shot. __________________ ASE Master Technician