For most people, electricity is one of those deep mysteries of life, made all the more intimidating because without it virtually everything in our lives would stop. This universal rule applies to your car, as well.

In order to check the electrical system on a prospective used car purchase, it is not necessary to go over the vehicle with a test light and a meter--leave that to the experts. You, however, can and should do some elementary checking to assure that the electrical components are in good working order.

Begin under the hood.
Look at the battery and the tray it rests on. They should be clean, with no powdery residue, no evidence of liquid leakage, no evidence of rust or corrosion. Examine the battery cables attached to the battery. They should be of the "one piece" type, with the clamp and cable an integral unit. If the clamp is one of the types that bolts to the cable, it could be evidence of earlier--and potentially future--problems. Examine the cable insulation. It should be intact, with no bulges or splits, which would indicate deep corrosion.

Now look at all the other wires snaking around the engine bay. Look for evidence of the original wiring harness having been opened up, a sign that some sort of electrical problem was part of the car's past.

Check-out the passenger comparment.
After checking under the hood, move to the passenger compartment. Before sitting in the driver's seat, kneel down and look up into the underside of the dashboard. If it's open (many cars now cover this area with kick panels) look at the arrangement of the wires. They should look neat, or "dressed," as they say in car talk. If you can get your head fairly close, sniff the underdash area for a burned smell--evidence of some underdash electrical failure. Do the same on the passenger side. If you do detect a burned odor, make another note for when your expert checks it out.

Then, sit in the driver's seat and turn the key to the "run" position without starting the engine. Look at all of the gauges and warning lights; they should be lit up. Burned out dash lights could be masking an engine problem; be especially cautious until you get an expert opinion.

Start the engine and try all of the accessories: lights, turn signals, wipers (all speeds), washer, rear wiper and washer (if equipped), horn, heater (all fan speeds), and air conditioner--regardless of the outdoor temperature, the weather will change. Check all of the power assists, too: windows, locks, seats, sunroof--everything. Test each switch by moving the accessory to full travel in every direction possible. Then do it again. Note if the accessory moves smoothly or if it hesitates or jerks, symptoms of potential motor or switch failure. Test the secondary power window switches, too. Open the doors to see if the dome light(s) come on. Don't overlook anything. Even if a particular accessory is not important to you, any deficiency will be useful when you negotiate the purchase price.