13BstreetportFB

so throughout the three years i've had this car its had a slow drain. very slow drain probably about every six months i'd have to recharge my battery. now i bought an optima and i'd have to charge it like every 9 months rather than the usual 6. i have a new alternater and new battery and the problem still occurs. now i do have an aftermarket stereo and alarm which is used to unlock the doors because the keys holes are shaved (otherwise wouldn't be able to get into the car besides the trunk). Also when i drive my voltage gauge stays at 12V rather than the normal 14V (i think)?

so i recently bought my first multimeter and i notice that when i check the fusible links for any volts running through it the middle link which is 1.25sq had 11.8 volts. so i started pulling out fuses and the only fuse that actually made a difference was the 15amp fuse responsible for the auto clock and the volts dropped from 11.8 to 10.8. is this right, it takes 1V to power the auto clock??? when i removed the fuse for my alarm the volts dropped from 10.8 to 0. now obviuosly the alarm needs electricity to function but it 10.8 volts normal for an alarm to function??

now for my main concern is why when i drive my voltage in my gauge cluster says 12V??? i know it should be higher. when i use my headlights at night, signal, or brake the gauge flickers. could there be a problem with the charging to the battery?? how do i figure this out with my new craftsmens multimeter tool i bought?? how can i figure out whether the wire that connects inside the car is still providing good current on the other end of the wire in the engine bay?? i really want to make sure i'm getting the proper charging supply back to my battery?? please help guys i need suggestions. thanks

Siraniko

iTrader: (13)

disconnect the 2-wire pigtail behind the alternator. then run a 12-V coil's + terminal to the alternator's F terminal. Refer to the pix below.

the upper wire on the 2-wire pigtail is where the 12-V goes while the loose wire is for the VOM. The alternator is good if get 13.5+ volts; otherwise, you have other issues. Clean the battery cable ends with that short piece of wire from battery to the fusible links. Thats where I would start. Btw, junk the stock fusible like and upgrade to a FC fuse box. The rest, it will cost you lots of heine's and korean bbq.

13BstreetportFB

alrite i disconnected the 2-wire pigtail behind the alternator. haha (no brainer)... but what do you mean by run a 12-V coil's + terminal to the alternator's F terminal???? sorry i'm a noob when it comes to the electrical issues with cars.

Siraniko

iTrader: (13)

the alternator requires a 12-V for it to start charging. The easiest way to get a 12-V is thru the battery or the coil.

rearviewmirror

If you've got a slow discharging battery then you want disconnect the negative terminal from the battery, once disconnected, connect an Ammeter between the negative post and the battery cable. This will show you current draw with the car turned off. If you're drawing 1mA that pretty normal, anything above that and your battery will be dead over a period of time. The higher the mA draw with the car off the faster the battery will discharge.

DavidMyers53

If my '82 is left sitting for 2 weeks, the battery dies. I figured it was the radio or something that is always on, so I put a quick disconnect on the negative battery cable. Takes about 30 seconds to disconnect when I know I'm not going to drive it for awhile.

- David

rearviewmirror

I would do the troubleshooting steps I pointed out above. Watch the current draw as a car shouldn't discharge over 2 weeks. Pull fuses 1 by 1 and see when the current draw goes to 0 or at the very most 1 mA. That will tell you what is drawing the current, and from that you can remedy it. I would not want to pop the hood to disconnect the car when I parked it, seems like a huge PITA.

13BstreetportFB

alrite guys here some feedback... i just did the alternator test thanks to wacky and i'm getting about 13.5... it was kinda hard to keep the probe on the alternator cause the motor rubbling so much. now, i know my alternator is good. how do i check the charge from the alternator to the battery?? is that what i did??? what wire do i check and how do i know if the wire is supplying the right amount of charge? im afraid that the car is so old the wires are starting to produce a lower voltage and amps.

for example: about a year ago my car wouldn't start. i figured out that it had to do with the wire that comes from the ignition key to the starter. i tested this with a simple test light. checked the signal from the ignition key the light was bright. checked the signal in the engine bay right after the plug under the brake mastercylinder and there was a faint of light. solution: rewired a whole new wire and bamm fixed the problem.

but how do i check the wires to see if they are up to par or just need replacement??

74RX4

iTrader: (10)

I would start by replacing both battery cables. If they are original they are almost definitely shot.

Howco

I had the exact same problem. Bout every 3 months I needed to charge my battery. Problem is our alternators are really weak. Run a wire from the post on the back of the alternator the one with the nut wired to it. Directly to the positive battery terminal. Also run another ground wire to the frame from the negative terminal.

After I did this my volts went up to 13 and I still have the voltmeter bouncing when I have the turn signal on but my battery gets charged and I have not had to take it out and put it on a charger since I did it.

13BstreetportFB

nice thanks... i found out guys i have a slow drain due to the CPU above the hood latch??? anyone familiar with these symptoms?