my 78 estate wagon keeps draining the battery as soon as i hook it up. every night i charge it up and as soon as i hook the wires up and try to start it i get nothing. the interior lights go on when i turn the ignition but when i try to start it it doesnt have the charge. i have tried a few different batteries and still nothing.. the thing dies even when i just try to turn the exterior lights on... please help im still trying to learn alot about this car, electrical stuff is not realy anything i have learned about yet... any help is greatly appreciated Vic
Install a digital ammeter between your neg post on the battery and the neg cable AFTER you pull the fuse for your interior lights. That circuit will blow your ammeter fuse. Read the ammeter. You should see current flow if you have a "leak." Then start pulling all the other fuses one by one until the ammeter finally reads zero. Record the current flow on paper and keep track of the circuit. Remember that some circuits draw normally to run the clock etc. The fuse with large amount of current flow is the most likely candidate. You can do some math and determine how many amphours are being drawn and then figure how long your battery will hold out. Either this month or last months CarCraft Magazine has an article on this subject.
Does it take a jump? You could have a bad battery cable.......the voltage drop from one end of the cable to the other should not be more than about 1 volt when the starter is turning. If the cable is bad, you'll have a lot more than that. Do this test with a voltmeter, positive to one end and neg to the other. Pos end of tester goes closest to the battery on the pos cable, neg from tester goes to the lug on the starter. Reverse when testing the neg cable. You may just have a dirty contact on the starter lug......hope that helps!
Have you checked the fusible links down at the starter? Try applying 12 volts to the "s" terminal of the starter. See if you are getting 12 volts at that wire when you turn the key to crank. You are assuming it's the battery. It could be alot of things. Draining a battery all at once would start a fire.
not only could it start a fire, it could very possably cause the battery to explode! By the sound of your description by the way I read it, it sounds as if the starter is bad.
