93 Grand Marquis Starting Problem

I had a weird problem. I hope someone can offer some insight.
My 93 Grand Marquis has 78500 miles. My wife took the car on Sunday and went a few blocks away to visit someone's house. She went in for
10 minutes, came back out and the car wouldn't start.
It wouldn't crank - instead it made a continuous clicking sound. She also noted that she had some trouble disengaging the alarm. I spoke to my mechanic. He said a continuous clicking probably means not enough power to the starter and suspected that this lack of power was also making the alarm misbehave. He suggested a boost - he suspected a weak battery.
The battery and alternator are a year and a half old. My went during the day and didn't use the lights and didn't leave them on (and even if she did, 10 minutes shouldn't have been long enough to drain the battery down).
I tried boosting it. Nothing. So I had the car towed to my mechanic. My mechanic told me, just for the hell of it, to try starting it when I got there.
I got the car there and sure enough, it started right up like nothing ever happened. And the alarm behaved too. Since he never actually saw or heard the problem himself, he can't say for sure what the problem was. He replaced the starter, figuring it's 11 years old anyway, even though he wasn't confident that was the problem.
He also said the negative wires to the battery connector weren't attached as tightly as he likes and noticed some signs of arcing in the connector when he redid and tigthened the connection.
I appreciate that he's honest when he says he really doesn't know what happened but it really bugs me that the problem mysteriously went away by itself.
Does anybody have any clues? Has anyone seen this happen before? I just hope that between the new starter and solid battery connections, my problem won't recur.
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Sounds like loose or slightly corroded battery connections to me. Boosting with anything short of welding cables won't help if poor battery connections exist since most the power for the starter must come from "booster" cables which are incapable of providing. Clean and tight connections are very important. Next time this happens, measure the voltage between the battery terminal and its cable clamp while cranking. Anything over a fraction of a volt is symptomatic of a poor connection. Stan K. JAG wrote:

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Another possibility- many Ford models have an underdesigned connector at the starter solenoid which corrodes and causes intermittent starting problems. It should be checked and cleaned every year or two on a car that old. Replacing the starter probably eliminated the problem for a while.

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Hi Jag, The 93 merc has a problem with a poor connection at the solenoid on the starter, a plastic there retains water & dirt & whatever else you may encounter and it does lose the connection often. You would be well advised to drill a hole on the lugs there, and use nuts and bolts to hold it together. Another point of interest is the ignition switch itself. HTH BeeVee

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