Looks like an aftermarket audio fuse or something. Definately not factory and shouldn't be in line with the starter/DME.

Check ALL the ground straps. Then remove them and clean them anyway.

100 amp too small for the starter. Would expect to have it blow if on the starter power.

The loose connection is definitely part of the stereo. It was pigtailed down to the connector near the battery.

After a free recharge at the store I hoped it back up but still have the same symptoms no crank at all from any starter. Now I have no power at all not even for headlights.

I wound second the suggestion to check the ignition switch.

How do I check the switch? The only thing I've found online is how to replace it, I haven't found yet how to check if that is the issue.

I'm still betting on one of the ground connections. Anyone want to start a pool?

On a productive note, have you tried using the black jumper cable directly from the negative battery post to the engine/transmission to make sure it is not a bad ground cable?

I haven't tried to jump it yet. I'll give that a shot either in the next hour, or tomorrow morning. Where do I find out how to check the grounds?

As I fixed the top part of that rogue wire, the bottom connector came loose. Since that's not my concern at the moment, I've removed it for the time being.

On how to check the switch - not sure if this is the same config in '88 as I had in an '83. If it is the same config as an 83, you can unplug the connector from the back of the ignition switch and plug it into a spare switch. My 83 had a problem where the key would jam and I couldn't rotate the switch to the start position. I had bought a spare electrical switch for my 83 that was just the electrical part, did not include the lock/key which mounted to the dash. I'd then use a philips head screw driver to turn the spare switch and start the car. You'd still have to buy the spare switch and I'm not sure of the config on an '88.

It's pretty hard to check the grounds, just easier to remove them all and clean them. Unbolt each of the ends, shine the ends of the braids and the mounting points with some steel wool, and bolt them back together. There are quite a few of them. As a minimum, the one from the battery to the frame and the one from the frame to the transmission.