I have a die hard battery that is about 2 years old. I am sure that I have an electrical problem somewhare that is draining the juice. I have to jump it and it stars right up. Any sugestions on how I can find where the problem is
thanks
Bmas

 

Start pulling fuses and check the draw on the battery each time. Also check your seat motors to see if there warm.

 

Have Autozone, Checker etc. check the battery capacity first. I had one Die Hard die in 18 months. Later! Frank

 

Why don't you tell us what year C4 you are asking help for????????????
First, always charge your battery back up overnight with a battery charger, and disconnect the battery until you find the leakage current. Batteries left discharged will sulphate the plates and decrease the amphour capacity until the battery is totally sulphated and dead forever.
At night, check for underhood lights, vanity mirror lights, door panel lights, console light, spare tire light. Do you have a radar detector, aftermarket radio, alarm, CB transceiver, or audio amplifier? Check em.
Disconnect the negative cable and remove the courtesy light fuse and underhood lamps, then connect an ammeter from the neg cable to the neg batt terminal. GM says leakage current should not exceed 50 milliamps (my 87 draws 27 ma.). Pull one fuse at a time while watching the ammeter. A sudden drop in current will identify the circuit that needs further investigation. Also, for early C4's there is a bolt behind the battery that has 8 red wires connected, each has a fusible link and you need to remove these wires one at a time while watching the ammeter if the fuses don't show the circuit with the excess leakage.
If you measure normal leakage current (less than 50 ma.), then you have a defective battery (charge it up first) that won't hold a charge. You can tell the state of charge in your battery by measuring the battery terminal voltage, 12.0 volts and below, discharged. 12.9 volts and higher, fully charged and linear in between.

 

I opened the door and the lights inside all work. Tried to start it and hurd one click and nothing . All the lights on dashboard lit up but no start. I hooked up my portable charger to battery and car started right up. I let it run for about 15 minutes then shut is off. I waited a minute and tried to start again but nothing.
Bmas
Thanks for your suggestions

 

Remove the battery cables (neg first) and clean the cable lugs, bolts, and battery terminals and replace the cables (neg last). If the starter will not work, then measure the battery voltage at the battery terminals while someone attempts to crank the engine. The battery voltage must not fall below 9.0 volts or it is discharged, cable connections are corroded, or the battery is at the end of its life.

 

im having about the same problem. i can jump start the car fine and itll run. i hooked up a volt meter after i turned it off and immediately it starting dropping voltage. when the car is running ive seen voltage from 12.9 to 13.6ish or so. voltage at batt was 12.9 with car off. ive tried a couple different batteries (friends had some) and read through the FSM and still kidna lost. i am wondering because in the FSM it says check belt tension and since i put my headers on i lost the brackets on the back side of the alternator. would that cause a loose belt?

sorry for the thread jack i didnt want to start a new post if i have about the same problem.

 

You need about 12.5 volts in the battery to operate the starter. A lower voltage will burn the lights and such and make you think all is well......when this may not the true! One of the best methods I have found is to place an amp meter between the positive battery terminal and note the current draw. Remove one fuse (from the fusebox) and record the reading. Continue doing this until you find the fuse that significantly reduces the current draw. If you have a circuit that has a short, this method should find the problem circuit. It will be up to you to locate the exact position of the short. This is not an easy problem.

 

Read my post, it is a lot safer to disconnect the negative cable and place the ammeter between the battery post and the cable! A wrench on the positive post shorts the battery if you touch the brace or the valve covers with the wrench.

 

ok well i dropped my car off at my mechanic and they said its drawing 400milliamps sitting. they went through the fuse test thing and did not find anything. they had my car prett ymuch on trickle charge the whole day. so i have to disconnect the battery whenever i park the car. so until get that fixed and also as a security thing im putting a batt kill switch on it until i can find the problem.

i asked one of the guys at my shop who is pretty good with electrical and he thinks a relay is stuck on somewhere

any other suggestions?

 

I believe on the 94, there are some fuses next to the battery. Connect the ammeter and pull the fuses one at a time. Also, there are several circuit breakers, I don't know if they can be unplugged. I haven't seen a 94 circuit diagram, but my 87 has 8 fusible links and if your 94 has fusible links (I am sure it does), those fusible links also need to be disconnected one at a time while watching the ammeter.

 

Now......I am going back some years on this....but I think a bad diode in the alternator will cause the battery to drain down. Some of you electrical gehrus may flame me on this

 

You are correct, a defective diode can draw current all the time and if you disconnect the output wire on the alternator which has a fusible link, you will see a dramatic drop in leakage current.

 

400 milliamp is still only .4 amps. While it will pull a good battery down eventually it should not in a few hours or even overnight. Later! Frank

 

im gonna have to try that out 2morrow after work.

 

My 94 is having the same problem. I just got a new diehard as the old one was about 6 years old. I parked it in the garage for a week when I went to start it it was dead,dead !! ?? I guess I'll try the fuse thing first

 

I forgot to say that the service engine light has been coming on regulary as well

 

The previous owner of my '94 said he had a battery drain problem and his mechanic diagnosed a problem in the alternator.
Installed a new alternator and no more dead battery.

 

this may be as simple as battery cables if they have corrision they will cause problems

 

take it back to Sears have them check the battery, could be a dead cell, never know, got to know your batteries good before you go any further....G