My parents’ 100 just experienced multiple alternator failures and I believe it was bad connections/corrosion causing the alternator to perceive a low state of charge and then cook itself.
It appears to be resolved after replacing the positive terminal clamp, replacing the ALT and ALT-S fuses in...
Anything is a PITA if old and corroded but that doesn’t matter the platform.
Nothing on the V8 is hard to get to. Like even the starter, yeah it’s buried, but you just peel some layers off and then it comes out. They really thought through the accessibility of bolts when designing that engine...
I’d hazard to guess that things wear at the same rate on both 80s and 100s, and both have a small handful of gotchas, but the 100 is far FAR easier to work on in my experience.
Even the starter under the intake manifold isn’t that hard. It’s such a well-designed engine.
Weeeelllll nothing is quite as fun as discovering your senile brain was probing the wrong wires the whole time.
Sigh.
So the only kinda-smoky gun was the original positive terminal clamp falling apart.
But at least that circuit has been thoroughly tested and I know for a fact that’s all...
Bingo. Perfect continuity from the ALT-S fuse wire to junction EE1. The culprit appears to be lousy fuse contacts in that battery fuse box.
Initially I wasn’t getting continuity on the side of the fuse contact that is actually attached to the wire, but I was reading 3.4 mega-ohms on the other...
Speaking of which, an update: I missed a part in the diagram where that ALT-S circuit passes through junction connectors 1J and 1M on the bottom of the main fuse block.
So gotta isolate the problem further. Hopefully pulling the fuse block isn’t a PITA.
The smoking gun has been found.
The ALT-S circuit, which tells the alternator how much charge the battery needs, goes from the battery, through the 7.5A ALT-S fuse, through junction EE1 (right behind the battery) and to the alternator plug.
Between the ALT-S fuse output terminal and the female...
Well we seem to be on the right track. The positive terminal of this brand new battery was already covered in that blue powder stuff, and the terminal itself tore apart when I tried to loosen it. That fuse box is also full of grime.
Gonna replace the terminal, clean the crap out of all...
I checked them all with a stethoscope, totally fine. The noise went completely away when the reman was installed and the car stayed quiet until this weekend.
Two months ago the alternator in my parents’ 1999 started making a weird whirring/moaning noise, and about two days later stopped charging.
Replaced it with a reman unit from my local dealer.
This week that unit started making the exact same noise. It’s still charging at the moment but the...
So lately my mom says her 1999 is way bouncier than it used to be. They got Bilsteins installed in it in June (not sure exactly which ones) and it already has a torsion bar crank + rear spring lift and 33-34” tires.
She says it started just a few weeks ago, and it does seem to get rather bouncy...