Project 666. Our '87 Ford Mustang. She's a beast, but we love her.

You learn a little something new everyday. If I hang around long enough, I’ll be a genius. Today’s lesson; Ford 2G alternators and fires.

Before you get the wrong idea, our stripper Mustang that we call “Project 666” is fine. We didn’t burn it to ground or anything like that.

We were having some battery and charging issues with our project car, and those issues led us to the alternator. Nothing special there, an alternator change is pretty straight forward, and to be honest, pretty boring.

We made a quick run to the parts store and pick up a replacement. Normally we hunt around and find a really cool aftermarket performance piece to replace the stock factory stuff, but we were in a hurry.

I opened the box for the new part and a piece of paper catches my eye. Real men don’t read the instructions but this paper looked different and important. So we gathered around to take a closer look:

Fire Hazard! This piece of paper must be important.

Very top line of the paper states in big bold letters: DANGER. FIRE HAZARD.
OK. Now they have my attention. I flip the paper over and the big bold letters on the other side say: PELIGRO. RIESGO DE FUEGO. I know what Fuego means from my many Taco Bell visits. Now I am more than curious and want to figure out what the 5 alarm fire warning is all about.

Not wanting to appear ignorant, or more than I already do…I bypass asking James. He has a lot of experience in these model Mustangs, and he’s my boss, so I head for the internet.

A little searching around and I get an education on electrical connectors and the factory charging system for the 5.0 Mustangs. I didn’t know this before, so I figured it was worth sharing. Check this out:

The stock 2G alternator.

The Fox Body 5 liter Mustangs were equipped with what Ford calls the 2G alternator. This alternator is rated at 75 amps which is ok for the electrical system on a Stock Mustang that doesn’t have power accessories. When you have one of these Mustangs though, they don’t stay stock long. Much like our 666 Stang, modifications are common, and many of them are electrical.

That is when the problems start to come into play. Electric fans, water pumps, nitrous solenoids and such, start to draw more load than the alternator can keep up with. Best case scenario; the alternator quits. Worse case scenario; Fuego.

The bad guy: the two wire spade connector.

The stock wiring harness and alternator has a three spade design, of which, two spades share the current. Our connector was three spade but only two were in use, the third had a factory seal on the wire side of the connector.

So two spades are sharing the current and as the load (demand) increases, the resistance in the wires increases to the point of overload. Overloads create massive heat that can melt the wires and wire harness. Resulting in: yeah, you guessed it, Fuego.

Three spade connector on the alternator.

Ford recognized this problem in 1996 and issued a technical service bulletin. The update was an electrical wiring kit (part number E5AZ-14305-AA) to eliminate the possibility of Fuego. Accordingly, the new replacement alternators now have direct wiring and you must cut out the three spade connector and direct wire the new alternator in.

The new alternator. Hard wired, no more spade connectors.

Cutting the stock connector.

The wires from the new alternator are soldered together and covered with heat shrink.

A final wrap with electrical tape and she's good as new.