My van's battery light came on a few weeks ago.

The noise is low voltage. It sounds like the alternator has failed. You need a new shop that can repair the car correctly. The regulators are a rare failure. Thats why they moved them to the computers

Roy

I would be suspect of the diagnosis. Without seeing the testing myself, the voltage regulator in the Engine Computer is the least likely thing to cause a problem. By far the most common cause of an intermittent no-charge condition is worn brushes inside the alternator. The assembly costs around $9.00 and can be replaced in about an hour. On the easy-to-work-on '95 and older models it can usually be replaced without even removing the alternator from the engine.

Most shops and mechanics will not do this repair for a couple of reasons. First, the additional labor time brings the cost to you up almost as high as the cost of replacing the entire alternator. Second, there is a small chance something else is wrong and the new brushes won't be the solution, then their time will be wasted. A rebuilt alternator will also come with a warranty and it will have been tested.

The way to find this is to measure the voltages on the two smaller wires on the back of the alternator. This must be done with the engine running and while the problem is occurring, (battery light is on). The alternator is going to test okay if the testing is done when the battery light is off.