Hello, I have a 2002 Excursion XLT 2wd V8 Automatic trans pretty much base model. 2nd Exc I've had (1st was 2000 limited V10)...probably will always have one as it's my favorite model of vehicle ever. I know next to nothing about electricity or cars. I have about as much business messing with my truck under the hood as I do performing brain surgery and no I am not a doctor.

Anyhow, about a week ago, when leaving from eating out, the Ex would not start, acting like the battery was dead. I looked under the hood while my wife looked for someone to give us a jump and noticed that the black/ground terminal seemed loose. I wiggled it slightly and it came right off so I put it back on and turned it until it felt tight and boom started right up. So, being the all knowing genius and everything I decide to replace the ground terminal with a nice new neat black painted one. With my best buddy google I found how to replace it and seemingly did it correctly. As there was some bare copper between both the black and red wires where they connected to each terminal, I wrapped them both with electrical tape...even being so snazzy as to use red tape on the red wire and black tape on the black one. Well, it looks really nice, however it is now dead as a door nail and acts like there is no power anywhere within the car electrical system...no lights, no turning over, nothing. This morning I went to leave for work in my wife's Fusion and I went to put some of her stuff in the Ex since it wouldnt be going anywhere. Well, I opened the driver side door, the interior dome light and running board lights came on...woohoo i'm saved. Ran in house to get key came back...dead...nothing...zip. Read some more google wisdom which suggested it might be something called an open circuit. Checked to make sure grounded...grounded. Had brilliant idea to touch both posts of the battery with opposite ends of a piece of 4 gauge wire I had...shocked the crap out of myself. Tested resistance with cables disconnected...circuit is closed...resistance exactly same as it is when touching to terminals of meter to each other. Now very frustrated looking at having to go another day without my baby and have her towed 10 miles into town because I was dumb enough to think I could fix something that wasn't broken. I've apologized to the truck profusely and promised never again to tamper with her innards, but she is still dead. I would really appreciate some wisdom and guidance other than "you shouldnt mess with car batteries" which my 5 year old son has let me know many times since yesterday. Thanks for reading my rant and thanks in advance for any suggestions. You can call me an idiot as many times as you like if you can tell me how to get the old girl going again.

 

Have you tested the voltage at the battery? It might still have enough juice to turn on the lights but not enough to crank. Are you hearing a click noise at all or no? If yes try tapping the starter lightly with a hammer and cranking... have you tried starting it in neutral? Have you tried using your Fusion to give the Ex a boost? I'd try simple things like this before getting too "google-y"...

Are you sure you installed the new negative clamp correctly?

 

That is a perfect example of a bad connection either at the battery, the ground to the block, or the 12+ connection at the relay on the fender (I believe on the fender with that model).

The new black terminal you put on, was the inside (part that contacts battery terminal) clean or have paint on it? The wires are connected and bolted down nice and tight to the new terminal and the paint also cleaned off where the wires contact the terminal?