I am quite new to this forum.......

I have a 1993 JGC, 4.0L 6cyl. 4x4

It starts fine, but as soon as any electrical contact is made, such as pushing the brake pedal, using the power windows, turning on the lights, anything, it seems to short or draw all of the electrical power down, and nothing will work. I had it towed home the other night, and when it was in the driveway, it worked fine. It seems to be somewhat intermittent.

Please help......thanks

Phillip

Start with the basics!!!

Check the battery condition. Disconnect the battery cables and test the battery voltage with a volt meter. Should be 12.6 volts. If not, charge the battery and retest it. Once the battery voltage is confirmed at 12.6v minimum, test the specific gravity for consistant reading between all cells (maximum difference of 50 points on the scale)

If that is ok, then it is time for a load test. Some auto stores will do this for free.

Clean the battery posts and terminals and reinstall the battery. Start the engine and check the charging voltage at the battery posts with the volt meter. Should be 13.8 to 14.5v. now turn on all the accessories you can and recheck the voltage. It should hold at what it was before.

You can also check the voltage while cranking the engne. Voltage should not drop below 10.5 volts. The higher it stays, the better off you are.

I would pick corroded battery posts as the likely cause but you need to see what is happening with the battery too.

Once the battery is known to be good, then if there is still a problem, it can be handled at that time.

JD

I appreciate the help.........the battery is good, as well as the charging system, it held at between 13 and 14 volts. I wonder if a faulty voltage regulator would show an indication?....I read it was housed either in the alternator or in the PCM.

It seems not to draw down the voltage, however, operating any accessories when the problem occurs dims the lights, shuts off the radio, and knocks out the gauges......quite frustrating.

Thanks

If the battery is good and the posts are clean where they contact the inside of the clamps on the cable ends, then there must be a ground problem.

Check the ground cable where it attaches to the engine block. Loosen and retighten the bolt holding it.

Check the terminals of any other ground wires from the battery to the fender sheet metal. Loosen the bolts and retighten them to make sure contact is good. Sometimes the bolts in the fenders will strip out if they are selftapping type of threads.

JD