Last night I left my keys in my ignition for a few hours with ignition off. I drove the 3 miles home and on the way noticed my battery light was on strong and all my instruments didn't work including the small gauges. But the car was driving fine. I had noticed the last few weeks that first thing in the morning the car lacked power. I thought a few days ago that I noticed for a split second a warning light flicker on then off but couldn't make out what it was.

I checked the fuses and found fuse 13 had failed. I regained my small gauges and idiot lights.

Today I started looking at the ground on the alternator and found a little suspect on one end of it. Although I have had a bad ground and the symptoms where all my idiot lights glowing until it broke. I have a new in the box Voltage Regulator and decided to swap it out to eliminate it as a possible problem. The old one was only maybe 30,000 miles old and worn unevenly on one brush over the other. Possible messed up installation job last time. After replacing the VR the car wouldn't start. So I was now going backwards.

I swapped out a spare coil and that didn't help.

All my searching on the brickboard didn't turn up anything promising and my Bentley manual went missing over the past year. I have a used spare ignition switch so I swapped it out to eliminate that. That didn't do anything other than crank my neck and shoulder.

Because the car was in the direct afternoon sun I delayed checking for spark although the fuel pumps were working so I felt that eliminated problems at the distributor's CPS.

In my search for the spare ignition switch I came across another spare coil I kept in the car. Knowing that it worked a few years ago when tested I swapped it in since the tachometer was failing to show any signs of life. Car fired right up.

So strange to me that a failing coil could keep a car running while at the same time trigger the battery light. Or did it? I failed to mention that while messing around with the alternator I by accident touched the main big wire terminal with a screw driver grounding it to the body of the alternator. Maybe that killed the coil?

Will a dying Coil trigger the battery light and cause gauges to stop working including the tach, speedometer, temp, and fuel?

On a side not I realized today I've been driving on a good battery made in 2008. Its a Diehard.