1989 Pontiac Sunbird not charging

If you didn't correctly hook up the alternator, it will not charge the system. What size engine do you have?

I would first check to make sure everything is hooked up correctly. This actually happens a lot, I would double check everything and then if it still is not correct, most part stores will do it for free. You can also use a volt meter to see if there is any output.

Sean

2.0 is the engine size. We have checked to make sure it was hooked up correct. When we hook up a voltage meter to the battery it puts out the right voltage but when we start the car the voltage goes down to 11 volts. Please help I am puzzled. Thanks.

It sounds like the alternator. There should be a four-way connector to the alternator. This is what tells the system to charge or not. (Regulator) I would check to see if any wires are exposed or disconnected from the connector. Also make sure all the terminals on the battery and alternator are tight and clean.

Sean