I recently spoke to a friend of mine named Mary...
I recently spoke to a friend of mine named Mary who is currently doing charitable work in Romania and needs your help. She has a 1986 Chevy 4 X 4 pickup, U.S. army surplus from Germany. It has a problem with the battery. It's a diesel, with power steering, and automatic transmission. The problem is that the battery will not hold a charge if it is hooked up. It holds a charge if left disconnected or taken out of the truck. How can she tell what's wrong?
RAY: She's going to have to do a little research, John. Some electrical device is draining the battery when the engine is off. It could be the glove compartment light, the clock, or any number of things.
TOM: And here's how she can find it. Tell her to get a 12 volt test light. Have her disconnect the cable from one terminal of the battery, and put the test light between the cable and that terminal. The light should go on, confirming that electricity is being drawn from the battery (by the way, make sure she does this with the door closed, otherwise the dome light will be drawing current).
RAY: Once the test light is hooked up, the investigative work begins. And what she should do is remove the fuses one at a time. Every time she removes a fuse, she should check to see if the test light has gone off . When it goes off, she's got an enormous clue.
TOM: For example, if the fuse that makes the test light go off is for the tail lights and the seat warmer, she's narrowed it down considerably.
RAY: There's a chance that none of the fuses will make the test light go out, in which case she may also have to try disconnecting the alternator, or any other electical devices on the truck that don't have fuses.
TOM: When she's identified the offending device, she'll have several choices. It may be simple enought that she can fix it herself or find some nice Romanian electrician who can fix it. Or, if it's something she can live without, like the cigarette lighter, she can just disconnect it.
RAY: Or, if it's something important, she can bop down to Transylvania Chevy/Geo and pick up the part. Or, if they're not open this week, you can go to your local Chevy dealer and send her the part, John. Wish her good luck for us.