car wont hold a charge.

Topic: car wont hold a charge. (Read 1249 times) previous topic - next topic

car wont hold a charge.

September 15, 2008, 04:48:28 PM

its an 86 turbo coupe if that helps. I can jump the car and keep it running ONLY if i keep the jumper cables connected otherwise it looses power and dies. I would assume this would be the alternator but i was wondering if there were other things i could check with a 12v meter. Im no electrical wizard, but if there are things i can check before replacing the alternator it would be much appreciated.
thanks,
dan

car wont hold a charge.

Reply #1 – September 15, 2008, 05:53:42 PM

Does the Batt(Alt) light come on with the ignition in RUN before you start?
Does the light go out after it starts?
Can you install the good charged battery in the car?
The battery voltage should be 12.5v before you start. It should go up to 14.5v volts after you start if the alternator is working.

car wont hold a charge.

Reply #2 – September 15, 2008, 06:16:14 PM

thanks ill have to jump it agian and see what happens.

car wont hold a charge.

Reply #3 – September 15, 2008, 08:12:23 PM

also, on most older cars there is a external regulator for the alt. That could be fried too.

car wont hold a charge.

Reply #4 – September 16, 2008, 04:07:55 PM

its just weird because i took the car apart to paint it and i havent driven it in forever. now i try and move it and it wont hold a charge.

car wont hold a charge.

Reply #5 – September 16, 2008, 04:39:06 PM

Needs a battery for sure and possibly an alternator.

car wont hold a charge.

Reply #6 – September 16, 2008, 06:16:16 PM

How old is your battery?
Are your cables and connections OK? --No corrosion?

car wont hold a charge.

Reply #7 – September 17, 2008, 02:50:32 PM

If you want to troubleshoot it here is what you do:

1. Get the dead battery out of the picture. Remove it and install the good battery you are jumpering from. If this is not possible, disconnect the negative battery cable from the dead battery. Hook your negative jumper cable to the disconnected negative battery cable. Hook your positive jumper cable to the positive battery post.

1a. If you are jumpering from another vehicle it should not be running. To be safe disconnect the negative battery cable in the donor vehicle.

2. Look at your alternator and notice the laminated plates. This is the core for the field coil magnet. Touch the laminate with a nonmagnetized screwdriver (one that will not pick up a paper clip). You should feel no magnetism at this point.

3. Turn the ignition to RUN. Do not try to start. If you have a red battery logo light, it should be on. If you have an ammeter you will not have a battery light.
The alternator field coil should now be energized. Feel for magnetism at the alternator laminate with your screwdriver.

4. If no magnetism, let us know if you have a red battery logo light or an ammeter. Also if you have an internal or external voltage regulator.

5. If you have magnetism, start it up and check for 14-14.5 volts between the positive battery post and ground.

Let us know what you find.

car wont hold a charge.

Reply #8 – September 18, 2008, 12:48:58 AM

softtouch
The only thing i would add to that write up is this...

Connect the jumper cables up to the GOOD car first , then connect to the BAD car.
Disconnect from the BAD car first, then disconnect from the GOOD car.

Doing the above insures the spark/arch occures on the bad car when connecting or disconnecting jumper cables.
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Connect the jumper cables up to the GOOD car first + then -,,,,,,then connect to the BAD car + then -.
Disconnect from the BAD car first , - then +, then disconnect from the GOOD car, - then +.
Doing the above insures the spark/arch occures on the bad car and also insures the spark/arch happens on the ground side.

I like the process you did up.:bowdown: