Battery or Alternator?

Question

I have a 1996 Toyota 4Runner that has been sitting, not driven for almost 4 years. Six months ago we moved and when we went to start it, it was dead. We jump started it, let it run for about 20 minutes and then parked it. A few days later we moved and before we left, we started it, it started fine. We got to our new place and parked it. Didn't re-start it for another 3 months, tried again, battery dead. Bought brand new battery, put it in, worked fine. Parked it for another 3 months without starting it. Now, we are going to start driving it because we live in the mountains where it snows and want to get it ready for the winter. Went to start it today with the new battery, didn't start so we jump started it. Let it run for 20 minutes, moved it and turned it off. I tried to re-start it as soon as I turned it off and all I heard were clicks. No lights, no interior lights and no radio. Does this sound like battery or alternator?

Answer 1

I have to disagree with Fordman, even though his answers are usually right on the money. Disconnecting the battery cable while the engine is running can induce a huge voltage surge into your electrical system and fry your computerized components. If was a great way to test an alternator back in the old days. Today it can cost you a cool thousand bucks.

The best way to test an alternator is with a voltage meter. It should put out at least 13 volts. However, it needs a fully charged battery to do its job.

One of the mistakes you make is to think that an alternator can charge up a dead battery. It can't. If it doesn't get 12 volts, it can't generate electricity.

But Fordman is absolutely correct that you cannot leave a battery in a discharged state. If you can't drive the car, get a "battery maintainer" charger. They are better than trickle chargers because they only charge the battery when it needs charging. Trickle chargers are on all the time and can overcharge a battery.

Rick

I'm a retired ASE Master/L-1 Technician. I still keep current with the latest automotive technology. Visit my blog for cool articles and TSB's: http://free-auto-repair-advice.blogspot.com

Answer 2

Could be Both!

1; Take the battery out and have it put on a Slow Charge for 8 to 12 hours then if it's up to 12V or 12.5V have them "Load Teat" it to see if it will hold a charge. In 12 to 15 seconds it should hold a charge of no less then 9.6V.

2; Battery could be draining down because of a "Bad Diode in the Alternator" Loose or bad battery cables.

"Checks and Repairs after sitting 4 Years"

1; Change Oil and Oil Filter! To be Safe you might want to "Flush the Engine!"

2; Change Coolant and Thermostat (Coolant should be changed every 12 to18 months, Thermostat maybe damaged from coolant after so long. Coolant mix should be 50/50 Water and Anti-freeze.

3; Check tires for "Weather Cracks and Pressure"

4; Remove wheels and check Brakes and Wheel Bearings. You may want to drain and replace the brake fluid.

5; Check Transmission fluid/Grease and Gear Grease in Rear End.

6; Lube complete Chase and Drive Train Assembly.

7; Check all Vacuum Lines.

8; Run Carburetor/Injector through the Tank and engine, Two or three bottles, One bottle per-tank (3/4 full) every two to three weeks.

NOTE; If the battery goes dead (Flat) the alternator isn't make to fully charge a dead battery, Just build up a battery that is down a little and maintain it.

Good Luck!

Answer 3

Sounds to me such as you have have been given a parasitic draw someplace on your electric powered gadget. First close off each and all the motor vehicle's lights and upload-ons then close each and all the doors. With the battery interior the motor vehicle, first eliminate the unfavorable battery terminal. Now, applying a multimeter set to the DC volts scale placed one probe on the unfavorable terminal of the battery and the different probe to floor. examine the meter. in case you examine better than a pair of quarter of a volt, you have a draw someplace. Troubleshoot the draw by potential of having somebody eliminate fuses separately till you notice the meter voltage drop. once you notice the voltage drop, you’ve chanced on the circuit in which you have a power drain. thoroughly learn that circuit, area by potential of area, till you detect the reason at the back of the voltage drop. Isolate and fix the situation. If this does not fix the situation, take greater shield some days and notice that each and all the lights are off till now you walk faraway from the motor vehicle for the night. it would desire to be some thing so straight forward as a door that hasn't closed completely, inflicting an indoors easy to stay on in one day or perhaps a foul turn on an below hood or trunk easy. Any of those are better than sufficient to do the activity. i've got carried out it myself, better than as quickly as. many times, an entire battery value will shield it. Even a bounce start up and dealing the motor vehicle for an hour or so could build your battery up sufficient to get you going lower back as long as your alternator is doing its activity. There are diverse techniques that gets you the respond you prefer, it rather is barely between the suggestions on a thank you to end the comparable component.

Answer 4

Letting batteries set in a discharged condition is very hard on them. I would think that you have trashed the battery again, by not keeping a charge on it.

One way to tell, is to jump start the car, and then remove the positive or negative battery cable. If the car continues to run after you pull the cable then the alternator is doing it's job.

You may want to invest in a small battery charger and keep it plugged in to the battery so that you always have a charge on it.

good luck.

Answer 5

The battery is toast.

Answer 6

sounds to me like you better clean the battery terminals and posts. Get a battery brush at auto supply and clean 'em till they shine. Problem solved.

Answer 7

it sounds like its the battery, but it also sounds like you have an electrical gremlin that is drawing juice from your battery.

Answer 8

Alternator Definately ! (also check your Carbon Bushings - connectors - it's probably the coil in the alternator)
Fond regards
Sanjiv

Answer 9

yeah your battery is toast. replace it.