I have a 74 dart sport slant6 automatic and for some reason its killing a battery in less than a day of sitting. What could be causing it to die so quickly? Please help!
do you have a digital volt meter.... they cost 15 to 25 bucks...with a fully charged battery... engine OFF... key OFF.. drivers window open.. door closed..hood light disconnected...disconnect one battery cable either use your digital volt meter set to 15 or 20 amp DC scale.. the test leads in the proper location on the meter.. or your test light.. so.. negative post... test light or digital volt meter.. Negative cable.. read the amperage.. a 74 dodge dart should have NO draw at all.. unless you have an aftermarket car stereo.. those will usually draw about 0.010 milliamps. if you find current flow.. you will need to open the drivers door.. figure out which is the dome light fuse.. pull that one first.. check the amp draw... keep pulling fuses one at a time.. until the amp draw drops to zero.. don't forget.. there maybe a light in the glove box.. some models also have rear seat lights in the rear pillar that may not be visible from the front..i have several tests for you ..charge the battery on a charger at 10 amps or less until it passes the first part of this test..print this test... so you can follow it at the car... post results by number 1. 2, 3, 4,
I agree with the tests above and would like to add pulling the wires off from the alternator as a step. If it has a shorted diode, it will drain through the alt. I have also seen a starter drawing almost 30 amps while sitting, and then disappear after the battery was unplugged, then reappear later. Hope that this helps
+1 Mark4X4. Thats usually something that rarely gets checked. A defective diode will flow current in both directions. When a properly operating diode will flow current in one direction only. If the alternator is not charging, when checking the diode circut with a DVOM it be read as an open circut. Most of the time an alternator will get replaced when you can just replace a diode pack. Most Good auto parts stores will have replacement parts.(Much Cheaper) If you are doing such a job also check the bearings or the bushings. It doesn't take any special tools to do this either. Just regular hand tools.Bob
testing the system... disconnecting the Various alternator connections needs to be done with the ENGINE OFF...if you disconnect the alternator with the engine running.. or pull a battery cable with the engine running.. you will destroy the alternator ...what causes the alternator to fail if you pull a battery cable with the engine running or the output wire is removed or falls off while the engine is running...without the load of the battery limiting how high the system voltage can ***when the battery or alternator is disconnected.. the current still in the spinning rotor will create a voltage spike before the regulator can reduce the voltage ...this voltage spike can exceed the diode voltage rating.. either blowing the diode open or shorting it closed... this can happen part way and create a draw.. or all the way and create a DEAD short that will melt the insulation off the wire as the wire burns.. usually there is a fusible link somewhere in the system... sometimes that gets bypassed by a unknowing owner or mechanic..