1999 DODGE CARAVAN Engine Size : 3.3
Question: GOOD BATTERY. ALTERNATOR CHARGING FINE. TAKE OFF GROUND CABLE AND WILL GET A SPARK AND BATTERY WILL GO DOWN OVER NIGHT. NOTHING ON THAT I CAN FIND. I AM MECHANICAL MINDED AND HAVE A MECHANIC HELPING AND CANNOT FIND PROBLEM. MOTOR SEEMS TO BE HOT WITH A TEST LIGHT. ENGINE RUNS FINE. PLEASE SOMEONE PLEASE HELP. THANKS,GEORGE.
Answer: It sounds like you are telling us you have a problem with a battery going dead overnight. The alternator is charging fine. This is also called a "Parasitic Draw". You say motor seems to be hot with a test light. Not sure what you mean by that. If some motor- like wipers, window, etc is hot, then that may be your draw on the battery. To test for a draw with everything off, disconnect the negative cable from the battery, use a multimeter on the Amp scale with the leads inline between the negative battery cable and battery post. There should be no more then 50 miliamps- or .050 on the meter readout. Using a test light can be misleading.
But if that is how you are doing it, use your test light and remove fuses one at a time until the test light goes out- then that would be the circuit that is drawing down the battery. The test light may be very dim and hard to determine how much draw there is.
Comment: You say that the motor on your Dodge seems to be hot. What motor? Wipers, window, seat ? Whatever is hot, disconnect it and see if the problem goes away the next day. If it does then the issue most likely is not the motor itself, but the control circuit.
You will need a wiring schematic. You will need to test for a parasitic draw. This can be done with a test light, but a meter is much more helpful. If it is suppose to be powered all the time but activated by completing a ground, then the ground circuit must be staying on. If it is not suppose to have power all the time, then use a test light to see if it is. If so, your problem is in the power feed circuit staying activated.
It all depends on what system is acting up for you to get a wiring schematic for your Dodge. You can also just start removing fuses to see what circuit is staying alive and draining the battery overnight. Common circuits to stay awake are seat motors, ABS units, transmission control module, radio, interior lights such as glove box or lighted vanity mirrors, rear cargo light or any small ones like that.
