280c Battery Light Stays on when Key removed
 

Hello All,

I am new to forum, and in process of purchasing a 1975 280C with approx 80k miles in overall great condition. Problem is the owner was trying to charge battery for a test drive and connected the battery charger to the wrong terminals (replacement NEG cable was red).. We were able to jump start the car and drive it a short distance. When car is off and key is removed the BATTERY indicator stays on, and goes out when you drive. I know its not charging the battery because I can only go a short distance before car dies and needs to be jumped again. We tried a couple of new batteries and same thing happens. Before I spend the $$ for the car, would like some advice of things to check first. I did drive the car before this happened over the summer and she is really smooth. Any leads would be appreciated.

Thanks Dennis

You need to replace the alternator, one of the diodes that changes the current output from A/C to D/C is defective.

Thanks MB Doc, I will give him a call and see if he will purchase a new altenator before I pursue the car.

Dennis