I told you guys about installing my msd ignition. After getting everything installed and after getting my car running again, I was experiencing what the msd instructions called, "engine run on" which means the car was continuing to run after the ignition was turned off. So I installed the little diode that comes with the msd kit and it completely solved the problem. My question is, why did it also fix my fuel guage that was constantly reading full after I installed a new sending unit and guage? I thought I had a polarity issue, and now it works. You mean to tell me that this little diode that took about 3 minutes to install did all that? Can someone help me understand how that had anything to do with my fuel guage? Thanks

 

You connected the diode to the idiot light/indicator wire at the alternator? That is weird, because a diode is basically an electricity "check valve" that doesn't allow power to flow backwards (your feedback & run on problem). They don't change voltage value. Not to mention, the gas gauge works off of constant voltage, but varying degrees of ground (the float/wiper in the tank). Hey, at least it works now!