I have bought a new battery, replaced the cables, alternater is good and still the battery dies about once every 2 weeks. It is my daily driver so it is started up almost every day. I missed driving it one day this week and now it is so dead, I dont even hear the clicking that usually associates a dead battery. I had to check under the hood just to make sure it was still there. Im looking for ideas. Thanks! --Rick
Even though you say the alternator is good how do you know? I've had them checked at the parts stores and been told GOOD! Still drained my battery. I've heard that if a couple doides are bad in the alternator it will still test good, since it still charges but the bad diodes will put a drain on the battery when it's not being charged. Clint
I had the same problem, and I put a big, healthy ground strap betweent he engine and the body, and it cured the problem. Make sure the attachment areas on the engine and body are sanded to shiney metal, and tightened up real well, and see if that helps. Also, see if there is a drain by any of the stereo or electronic gauges, etc. Hope this helps.
That's a good point. I went with a monster ground stap also. People tend to ignore the battery cables and they can cause alot of problems and make you think something else is wrong. I was having a slight mis under full throttle. I'm running all MSD stuff and it turns out my ground cable was corroded up inside the jacket causing high resistance. Changed it out to the monster cable and it cleared right up. clint
i had a prob like that it was my alt belt was charging enough to keep the alt light off but not enough to re charge
with the engine off take a voltmeter and check to see how much draw is on the battery........shouldnt be any draw at all..... then start the car and see how much is in the battery again.....should be about 12-14 volts.... could also start the car and then disconnect the negative cable...if the car dies the alternator isnt putting anything out..... battery is only used to crank the starter...once the car is started then the alternator takes over
Too check for voltage draw would'nt he need to disconnect the negative cable and place the meter between it and the battery? Then use the Mili-volt setting? Is that right, it's been a while since I used a multi-meter. clint
Doing it like that you would need to isolate anything that would normally draw voltage like a clock or the radio memory. clint
true...i forgot about the clock....but it would check to see if anything was drawing from the battery and therefore killing the battery i had a 1972 charger that went through batteries until i found that the trunk light was always on becuase the mercury in the switch had grounded out and the light bulb was always on...
Honestly what you need to look for is amperage draw.YOu need to turn key off hook an amp probe to DVOM and see what is being pulled out of that battery when the car is in a non used and non running condition. Then start pulling fuses and see what stops the amperage draw. The fuse should Narrow the problem down a considerable amount. May not pin point the problem but will get you in the ball park. Then start disconnecting associated accessories that use that fuse/circuit until you see a change in amperage draw. I would suspect your problem is very subtle so it may be a very small current draw(amperage) so pay close attention.
In the past I have started the car and taken the cables off to test the Alt. and it kept running, so I figured that the alternator was doing its job. Today I went out there to jump the Mav and it didnt do anything! I kept the cables on for over 10 minutes and there wasnt any juice at all. The starter cable looks bad and the solenoid looks old, so maybe change those two things out? Any other ideas?
I vote for a bad cable or connection and bad diodes in the alternator. If one or more diodes are bad it will still charge but will also drain the battery when not running.
So pretty much a new alternator is needed? I can live with that I guess. The other things will probably be done as well just because they look like they need it. What about the battery not charging at all when it is getting jumped? would that be just because it has drained it so much? I would think it would at least start on a jump if the alternator is bad.
Have you checked all of your cable and connections. I hate to throw parts at a car as I can't afford it. I once had problems and it turned out to be the ground cable corroded up inside the sheathing. Do you have those clamp on type battery cable ends where you place the cable under the 2 bolts and a strap to tighten it? Those can cause alot of problems. You say the battery is new but it might be worth getting it tested before you spend anymore money on it. I think the voltage regulator can cause a drain on a battery in certain situations also. Have you checked that it's working right? clint
some battery places dont check for bad diodes. But Im sure they did a load test. But it could be the alt.
