1997 Toyota Camry: testing alternator

toyota
camry

#1

1997 Toyota Camry - can alternater be tested by removing negative battery cable, while vehicle is running, without damaging vehicle? How many minutes running vehicle without cable?


#2

Don’t do that , you run the chance of causing expensive electrical damage. If you are in the US Autozone in most places will test your battery and alternator for free.


#3

Ok thanks. I just got a new replacement battery, EXIDE. The previous one bad. Not sure if the alternator drained battery. When car shut doen, AAA did a reading, alternator 14.2 with some ripples, battery bad. They only jump started the engine, did not fully charge battery.


#4

What does excessive ripples mean? Bsd alternator or bad battery?


#5

A battery - ANY battery (Automotive, 9V, Lantern, C, AA, etc.) - ANY battery - does NOT have ripples, It is a 100% totally flat output. DC. No ripples. It might be almost totally dead - but it has no ripples.

An alternator; generating power/energy via a changing magnetic field - does have ripples. Excessive ripples can indicate one or more of the diodes are going out; or the commutator is worn, etc. The energy generated by an alternator always has ripples - it is just that your battery evens those out - when they are not excessive. You have a new battery. Go to harbor freight / or Home Depot and purchase a cheap VOM (Voltage, Ohm, multimeter). Have vehicle off. Measure dc voltage at battery. Start vehicle. Measure Dc voltage at Battery again. It should now be higher. Around 1.5 to 2 Volts more, (about 14.2 volts or so) Or take to Autozone or some such and have them check the alternator. Ripples are to be expected. Excessive ripple is not good. The alternator output does include ripple. Excessive ripple is a problem. A battery has ZERO ripple. An alternator - even a brand new, premium fantastic one - does have output with ripple.


#6

Thank you. Yes, not the battery having ripples. The alternator read 14.2, excessive ripples, at the time the battery was drained, and auto shut down all electric, even door locks. Prior to putting in a new battery, I cleaned the positive battery post. There is a red wire, with half moon copper connector between 2 small metal plates, then placed on the battery post. Where is the connector wire suppose to be? Why is there 2 small metal plates? I put it back how it was after cleaning.


#7

Best alternator test I know of is an amperage test. Place the clamp on the cable connecting the alternator and the battery. With engine running, turnon everything… AC, fan,headlights, dome light, wipers, rear defrost, radio, etc. Now measure how many amps are making it to the battery, then how many are leaving on the cable running to the distribution box.