Dropped the cradle out of the car and the AC wiring was the casualty (forgot to disconnect). I know where the wire goes that I'm holding in the pic, but where does that larger one go that's stripped?

black wires are often Ground but not always.

You need to find the other end.

------------------
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave

Also, if you can't find the end, you can try elimination.

You can try using this diagram.

http://cliff.hostkansas.com...7FieroEng_wire_1.jpg

(Credit goes to PFF member Mike Gonzalez for posting that image in this thread: https://www.fiero.nl/forum/...110502-2-103239.html - I posted a link to the image because the image is larger that how it shows in the thread, but couldn't find a way to make it larger in the forum view).

Also Ω meter to the block or frame read 0Ω can tell is likely a ground but still find other end to be sure.

Look at left front of engine bay too.
Is 1 black ground from engine to frame there and if this is it, likely find other 1/2 of the broken wire.

Is this is bad then is a "backup" return ground to the block and alternator.
Main ground is braided ground block to lid frame.
Main ground isn't neg battery cable or small wire to battery... That big cable mainly only return ground for the starter. Small wire if there does same thing as other small grounds.

I don't think its ground the ac clutch wires tend to be black.

AC clutch wires are GREEN power and BLACK block ground.
Both are heavy gage on the Fiero.

Thanks for the input guys.

If it is AC clutch wires...
The Plug to the coil have a diode to stop major back feed power surges that can blow ECM Radio and more.
Same reason many Car Relay coils have diode built into them but AC coil is way Way bigger that dumps 600+ volts and plenty of amps when coil is turn off. Enough to jump the AC Relay contacts to kill that and other things.

Very likely that diode broke too and must be replace.
Is why many "pigtail" for AC coil has the diode and wires connected.

Example: Dorman 85143 https://www.dormanproducts.com/p-20711-85143.aspx

quote Originally posted by theogre: If it is AC clutch wires... The Plug to the coil have a diode to stop major back feed power surges that can blow ECM Radio and more. Same reason many Car Relay coils have diode built into them but AC coil is way Way bigger that dumps 600+ volts and plenty of amps when coil is turn off. Enough to jump the AC Relay contacts to kill that and other things. Very likely that diode broke too and must be replace. Is why many "pigtail" for AC coil has the diode and wires connected. Example: Dorman 85143 https://www.dormanproducts.com/p-20711-85143.aspx

Fortunately that one is still accounted for.