charge warning light

[1986SILVER720]

For the last 6 days the light would come on after starting and would stay on until turned off. The last 2 days the light would stay off while driving ,as soon as I turned the ignition off the the light would come on and stay on until I started it up again. Now won't start. Anyone ever seen the the light come on after the ignition is turned off? Please help.

[datzenmike]

Normal operation is as follows. The charge light has battery on one side and the sense wire inside the alternator on the other. The sense wire connected to the diodes and a coil inside the alternator that produces a magnetic field. Turn ignition to on and current flows through the light to the alternator and the lamp lights. Turn ignition and after starting, the charge from the alternator diodes equals the battery voltage on the other side of the charge lamp, there is no current flow and the lamp remains unlit.

 

Daniel a member on here can explain this better I think but I would say one of the alternator diodes has failed and current is flowing backwards through it, turning the charge light on (even with the ignition off) and draining the battery over night. Most auto places will test your alternator for you.

 

 

Hope this helps, and welcome to Ratsun.