Some kind of electrical mystery! Help!

Here’s a mystery (well, it’s a mystery to me, anyway).



About a week ago, my 1997 Ford Ranger would not turn over. I replaced the battery and it ran fine for a few days. Then, as I was driving home on the highway yesterday, everything electrical started dead. Speedometer. Fuel gauge. Accelerator (fuel pump?). Figuring the brakes and steering were next, I pulled over and had it towed home.



Assuming I had a bad alternator, I hooked up the battery to a charger so I could drive the two miles over to a garage. When I tried to start the truck, it would not turn over, but SOMETHING started running, and making a loud humming sound. Water pump? Fuel pump? Leprechauns? God only knows. Anyway, the truck would not turn over and the mystery noise maker kept going until it ran the battery dead again.



So now I’m starting to think it’s not the alternator, but it’s something running when it’s not supposed to be, and stealing electricity from the battery faster than the alternator can put it back. Is this a valid theory? If so, what could be the culprit? Thanks for your help.

The only thing that can drain a battery that quick and make the noise you describe is a bad starter.

Tester

Makes sense… but I wonder why today it (the starter) kept going after I shut off the ignition and took out the key… it did not do this before, not even when it was apparently draining the new battery while I was driving it around for the last four days.

I’ve seen three Ford products with this problem. Two of them Rangers. And each time it was the starter. The possibilty could also be with the ignition switch. But I go by expierience.

Tester

Experience is one thing I obviously lack when it comes to vehicles. Thank you so much for your advice.