UPDATE: I had found a broken positive battery terminal. I always wondered why it was loose ever since I bought it. But this time it was real loose. The brass circular clamp had a crack in it, wouldn't tighten down all the way. That can definitely affect a starter. I've seen battery terminals physically move or "jump" when not properly tightened down and the starter is cranked. I added new (+) terminal lug to my fix-it list.
I put in newly rebuilt starter.
CLICK-CLICK
SH*T!
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Replaced (+) battery terminal hoping it would help.
Fired right up.
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So, a combination of things? Starter is definitely quieter. Rebuilder shop said it was simply all worn out inside. Looks like they put a whole new solenoid on it.
The battery terminal would also explain why I lost stereo power last week.
This may be the end of my problems, keeping my fingers crossed. I'll post back if the problem recurs.
FWIW, I took the starter off my silver convertible tracker and tried it in my tintop. It cranked over but sounded sickly, like a toy car whining. It worked. Put it back in the convertible and it sounded normal. Go figure: a starter sounds different on two vehicles with the same engine. Had BOTH tested and the convertible's starter tested out good and my tintop one had a nasty whine and click when engaging before rebuild. The housing/body on my tintop starter was about 2" longer than the convertible starter
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the shorter one had a "REMAN" label on it. The guy at the rebuilder's said that my tintop starter with the larger body was original since it had the "Mitsubishi" label and was a much better/heavier-duty starter than the reman unit and would withstand more abuse. Just letting you know that if you go get a reman starter from an auto parts store, it may be a whole different unit and not quite manufactured to OE spec. May last you a couple years, but my Mitsubishi starter worked for 21 years...