Questions and Answers

Mustang Blinking And Winking Q. Hi, I own a 1994 Ford Mustang GT 5.0 V-8 with 67,000 miles on it. I have begun having electrical problems, which are more evident at night. However during the day too I can see my battery gauge fluctuating back and forth like the voltage its getting is not constant. (Like it's a fishing bobber in water and its bobbing left to right) At night is when I can see all the different types of problems.

When I have my lights on, every couple minutes the battery gauge will jump to the left (decrease in voltage) and headlights and all my interior lights will dim really dark and then go back to normal. This will happen through out the duration of any drive. Even at night the battery gauge is wiggling back and forth like there is not a constant flow of energy like during the day.

Another thing is when I park and turn off my engine at night, all the lights will dim including the headlights and interior lights instead of staying at the same brightness as when the car is running. A couple other things I have noticed is that when I hit the brakes, the battery gauge also twitches and all my lights dim too. (Same as when I turn on my blinker as well).

And one other thing is after I park and have turned the car and all the lights off, I open the door and the interior light then comes on. Well if I tap on the break pedal it dims the interior light very low. I believe all these problems are connected but I'm not sure. I have a brand new alternator from the dealership and a very good high dollar battery.

What else could be causing these problems of what seems to be a bad connection or maybe a "lack of juice" somewhere? Any help would be greatly appreciated.

Thank you very much!
John

A. When this happens, it is indicative of a bad or weak battery. Now an expensive battery does not mean good battery so the first thing I would do is have the whole charging system checked, including a cell and load test on the battery, and a load test on the alternator.

If the battery, voltage regulator and battery check out, then I would suspect a loose connection at or (electrically) near the battery.