97 1.5l Mirage Battery wont charge.

[ts128158]

The cars battery finally gave out one day when I left the headlights on all day. I put in a new battery, by mistake did the same thing 2 days later. (Night shift, 80 hours a week for a month, I was fried) So I charged the battery with a jump from my other car acouple of times and finally borrowed a trickle charger. But the battery wont hold the charge. Well not that it wont hold a charge. It seems as though its not getting recharged from the alternator, I get very hard starts and sometimes none at all after I've started it a couple of times durring the week for normal drives. And will only be cured for a little while from a jump start or a few hours on the trickle charger. But once the car starts it runs fine. So, I'm getting power from the alternator to run the car, but its not charging the battery. What could be the problem?

[DFBonnett]

You need to check the output of the alternator with a VOM while the car is running. You want to see a minimum of 13.5 volts. Check also the condition of the cable connections at the battery and look for signs of corrosion under the insulation along the battery cables. It is also possible that the new battery may be defective. This is not unheard of.

[ts128158]

I put in a new alternator, I didnt test the output but I did check to see if there is good conection from the alt. to the battery. I used a battery clamp light and some wire, clamped one end on the negative terminal and the other clamp/wire on the output from the alt. and the light came on so there is a conection. The battery terminals are in great condition. But the battery isnt being charged still. And the battery will still hold the charge from the trickle charger. Could I have something running in the car thats draining the out put of the alternator before it can charge the battery? If so, what volts should the car be drawing while running and while its off and how can I test them?

[DFBonnett]

You can disconnect the negative terminal and run a 12 volt bulb between the cable end and the battery post. If it lights up you have a parasitic drain. Pull fuses until it goes out then evaluate the components on that circuit.

[ts128158]

Beautiful!!! Thank you very much! I didnt even think of that!!

[ts128158]

I just gave that a shot, no luck. My wife is picking up a voltmeter, I'll see if that says anything. Thank you for the help.

[DFBonnett]

You should get about 12.6 volts across the terminals with the car off and about 14.6 volts after first starting. This will taper down to about 13.5 after it charges a bit.
Don't assume the new alternator is good. Plenty of bad rebuilts right out of the box. That's why you need to check the output voltage with VOM the Mrs is bringing home.

[ts128158]

I tested everything. The battery was 12.5v by itself. With the car running it was 14.6v then to 14.2v and with the negative battery terminal clamp off the battery/alt read around 14v. I turned off the car and left the neg clamp off and ran the VOM between the neg terminal and the negative terminal clamp and there was a 10volt draw with the car off. Personally I thought that was too much. Is it? So I pulled the fuse that was causing the problem but now my interior lights and gauges dont work, so I'll have to pinpoint it further later on tonight. Thank you for the help DFBonnett.

[DFBonnett]

It certainly seems like you have a parasitic drain. Battery voltage looks go as does charging voltage.
You normally wouldn't be testing for a parasitic drain the way you did .
Try setting the VOM to DC amps. Disconnect the neg terminal and probe across from the neg clamp to the neg terminal. If you have more than 20 to 30 milliamps (mA) pull fuses again and see what you get. Don't start on the milliamp scale on the meter. If the drain is big it can blow the fuse in the meter. On the AMP scale you are looking for no more than .020 to .030 amps.
HTH

[ts128158]

The VOM my wife brought home the other night was frm my father in-law. And its some type of system anylizer. And it doesnt test amps, only cranking amps or something along those lines. She is getting a real VOM tonight however. I tested it again, and pulled the radio, which droped to voltage to 9.5v and I shut off the dome light and that dropped it to about 8.5v. So there is still some leak. Could it be the odometer or the speedometer? How would I test everything thats posible from the interior on this one circuit. Say like the dome light, how would I tell/test with the VOM from there the loss is occuring there? Thank you agian!!

[DFBonnett]

Do the amp test as discussed and see what you get. Then we can go from there. Also try disconnecting the alternator with the engine off and doing the amp test. See if that produces a result. I'm thinking there may be a bad diode in the replacement alternator.

[ts128158]

I tried to do the amp test but I fried out the fuse in the VOM. It only had a dc mA150 option. And I guess i was higher then that. So that answers that question. However, with further investigation with the technique I used earlier, I began pulling fuses and plugs from the inside fuse box/panel, with the orgional fuse under the hood inplace and the other VOM I had between the negative terminal and the neg. terminal clamp. I pulled one cable that powers the entire dash, lights, speedo, odo, directionals, warning lights and the radio. And the voltage dropped to 0v. So it further narrowed down the search a bit. When I pulled the fuse under the hood last time the speedo, odo and the radio shut off, and thats all that turned off, and the voltage dropped to 0v. So some of the same equipment is shutting off. I did however find something strange. The voltage with the radio removed went from 9.5v to 8v. I then began my search on the interior fuse box. I removed the "buzzer" on the back of the fuse box then the volts dropped to 5v. I then removed that cable and they dropped to 0v. Great I thought, but I plugged the cable back in to double check the drop, this time the volts jumped back to 8v again with the buzzer still removed. Either way I believe the problem may lie some where in my gauges. Does that sound possible from what I described above? Thank you again for your help! Oh, if it makes a difference the under the hood fuse that I pulled the other day is one of two that are connected to a yellow fuse holder for the interior lights. So I dont know if its two seperate fuses for the same line or 2 seperate lines to power the interior. If you own a mirage it might be the same for you.

[DFBonnett]

Are you sure you are pulling the right fuses? Normally one fuse, except possibly a master fuse or relay, would turn off all the things you describe. Have you found all the fuse locations? IIRC, they individual fuses are clearly marked as to function.
The Mirage I am familiar with is my daughter's '00 and since she no longer lives at home I can't run out and pop the hood or check the owner's manual to refresh my memory.
I believe you are on the right track, but you may be pulling the wrong fuses.

[ts128158]

I'm sure I pulled the right fuse. I thought it was strange too. The fuses are two 10amp mini fuses. Its like Mitsubi. split the interior lights into 2 10amp fuses instead of one 20amp. They both come out at the same time due to them being attached to this fuse clamp thing. After I take the holder out I remove one fuse (the problem one) and place back the other. According to the diagram on cover its the interior lights. I'm going to investigate further to see what the other fuse controls as well, but origionally I the volts didnt drop until I pulled to other fuse. The car has been acting better since I've pulled the fuse, but the odo/speedo doesnt work until I plug the fuse back in. But I'm having a problem with my Idle air control valve now as well so I think thats preventing enough gas at start up, I have to pump the gas a couple of times so it fires. So far the battery problem seems to be resolving so in the next couple of days I'll pull the dash and give another few tests on the equipment in there. Thank you again for the help.

[DFBonnett]

Have you had the new battery tested? When the original battery in my Crapillac was dead one morning after working perfectly the day before, I put the charger on it overnight and it showed a perfect 12.6 volts the following morning. I got one hesitant start, then the click of doom. A new battery was the cure. Apparently the old one only took a surface charge.
Before you go any further, test the new battery so at least you know what the problem isn't.
FWIW
YMMV