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?
Thanks!
Brad
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.
It could be a bad resistor, bad switch or just the brushes and such are worn out.
That can also be a bad alternator. I would have the charging system checked before replacing the battery.
My battery sort of died like that.
can't remember when the blower motor wa replaced...
it cranked right up. Got home, turned it off and
much surprises me anymore on a 28 year old truck...
before replacing the battery.
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 rectifier & 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.
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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.
Thank you.
Brad
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