Reader QuestionI might have hooked up my jumper cables backwards when I tried to jump start my 1999 Mercury Cougar. Now the battery light is on, and the battery will not hold a charge. What did I do?
If the jumper cables smoked and melted I can only assume that you did in deed hook the cables up backwards. I am surprised, and you should be thankful, that the engine will even start. Most of the time when this happens the alternator and the on board computer are toast, along with some wiring and who knows what else dies in the reverse voltage.
If you don’t see any obviously melted or damaged wires around the battery area, I would suspect you at least have a bad alternator, or a bad voltage regulator inside the alternator.
Check the wires at the alternator connector and make sure they are in good shape and plugged in to the alternator firmly. If they are, I would replace the alternator.
Usually when the red battery light is lit on the dash it is because there is no electricity coming out of the alternator making its way back to the battery. Since the reverse voltage, and the probable blown out voltage regulator.
Could you just have a bad battery? You could, I have seen a battery with a bad internal cell cause the red light on the dash to illuminate. Do you have another vehicle with the same top post battery style that you can swap out? You just need a battery with the same type of posts, on the same side of the battery so your cables will easily connect.
I really don’t think it is the battery, but it is quick to replace it with another one….maybe you have a good neighbor with a Ford vehicle that you can borrow the battery out of?
On the fuselink issue. If you had one, and it was damaged, it would probably shut off all power to the starter, so you would not have been able to start the engine.
Of course you should triple check all the battery cable connections and make sure they are clean and tight, and all wires and connections around the battery appear in good …..non melted shape.
Look in your phone book for an alternator repair specialty shop in your area, they will be the cheapest route to take.
Austin C. Davis