Double question (am I cheating?) ;)
Hey, do blower motors lose strength over time? I have a 1980 Bronco and I
can't remember when the blower motor wa replaced... but it's not blowing
very hard anymore...
Also, my battery died tonite - so bad it reset the clock. After 20 minutes
it cranked right up. Got home, turned it off and it's dead. Connections
are good. Never seen a battery do that before but not much surprises me
anymore on a 28 year old truck... Anyone seen that before?
Normally blowers don't get weak, maybe your a/c evac is dirty. First step is
to pull the blower and check for crap in there or the blower being loose on
the motor shaft. Also a bad connection could do that but it will usually
cook the area of the bad connection over time. So then you look for the
black spot :)
I have seen batteries do thing similars to your discription. But like you
said, it *sounds* like a bad connection.
My motorcycle had the same problem with the battery. It was a failing rectifier
in the charging circuit & everyone blamed it on the battery. Replaced the
& rode about 15 miles or so & the battery resumed a full charge for many more
years to come.
Bad resistor would lose lower speeds, but "High" works just fine and
dandy. Bad switch often responds to wiggling or twisting the handle.
Get a decent digital voltmeter, and see if you are getting float
charge voltage out of the alternator - 13.8 to 14.5 VDC at the battery
posts, depending on the outside temperature.
If the alternator is out, the most common failure point is worn out
carbon brushes on the field slip rings. You can replace just the
brushes if the slip rings aren't grooved badly, and keep going.
A rebuild job will change the brushes and the ball bearings, and ohm
out the field and the output windings, and the rectifier diodes in the
alternator output circuits. Anything that tests bad is replaced.
Your alternator actually makes 13V to 15V 3-phase AC (hence the term
alternator) that is rectified with six diodes (or an integrated
circuit style 'diode pack') to turn it into fairly steady DC for the
car systems, and the battery acts as a brute force whine filter to get
the last of the AC ripple.
A bad diode or two and the alternator will still work, kinda - but
it will also put out all sorts of radio interference noise. Will rip
up weak AM radio signals, and might even affect the strong stations.
--<< Bruce >>--
Holy. Thanks for the input guys. Now I'm just as confused as before. lol.
Changing the alternator on a Bronco is a pain cause the air conditioning
bracket has to come off if I remember. I once had Ford do it (New Years Eve
and I needed the truck, was in a different city) and they charged me $800.
At least they kissed me first. lol
I will try the voltmeter for sure.
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