More than likely. Get the clamp fixed! When going at speed, the clamp will vibrate, and will only be half re-charging the battery (the alternator re-charges it during operation). This means that when you slow down, you may not be getting any charge to it at all. Either that, or its just not making contact with the terminal when you have slowed down.
Will it even attempt to engage the starter?. If not then the battery or charging system needs to be looked at.
Because it's a Ford.
The fuses are located under the hood beside the battery.
I have had the same issue in my 92 gt and i replaced the fuel filter, vacume lines,and changed the tranny fluid and problem was gone due to one of the three changes
Your idle air controle valve.
I have an 82 Sabre and solved this by removing the battery probe and inline resistor, it unplugs from the sending wire at a connector a couple of inches from the probe. Connect the sending wire to any positive wire, insulate the connection to avoid shorting the electrical system. I kept the old connector intact and saved probe in case some time I will want to reinstall the battery probe.
With a volt meter or multi-meter. With the engine off the battery should read 12 volts at the battery posts. With the engine running it should read from 13.5-16 volts. Red positive probe goes to positive red post on battery, black negative probe goes to negative battery post or any metal ground on the engine.
The old battery was bad it could cause a power surge and plow the main fuse.
Get a standard 12v test light. Ground the clip and verify the ground by touching the positive battery terminal with the probe end. With the ignition switch turned to the run position, starting with the larger main fuse links use the probe to verify power on both sides of the fuses.
Take a DC volt meter and check the voltage at the battery. Red probe on positive + terminal and Black probe on negative - terminal. If it reads 12.6 volts it is fully charged. 12.4 and it is 75%, 12.2 and it is 50%, 12.0 and it is 25% charged. Less than 12 volts and it is considered a dead battery.
No, take the battery out and bring it to an auto part store and they can test it.
old and cold = bad battery