1993 Aerostar Charging System Problem

[remov1]

My aerostar with 192,000 miles recently showed a reduced voltage on the dash gauge but the charge light light did not illuminate. I took the alternator in and had it tested and they determined it was bad. I replaced the alternator and the battery for good measure since it was old but no change. Still indicating lower then normal voltage and still no charge light. I took the vehicle in and had the charging system checked and was told the alternator was not putting anything out. I removed it and took it in for testing and it tested good. When the vehicle is started the alternator initially begins to put out about 14 volts as it should but after a short time the alternator output dops off completely. I've checked the wires and fusible link but can't find anything wrong. I tested the resistance of the wire from the starter relay to alternator and it has a good connection. Any ideas?

[bertha66]

My 90 Aero was showing a drop in voltage some time ago, I tlked to a Ford shop and they pointed me to the ground cable. The ground cable insulation was cracked and some had come off. Old school thinking, I said that I did not think that it made a differance, ground is ground. But with newer computer controls it Does make a differance, ran a new ground cable and out put on the gage came bacd to normal.

[remov1]

Are you talking about the battery ground cable?

Internal regulator was checked during the alternator check and found to be good.

[cabowabo]

internal regulator ?

[bertha66]

Yes, the Battery ground cable is what I was talking about.