Whining Honda alternator

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Fri 19 Mar 2004 22:53
Whining Honda alternator - Mikey Jay
The car, a Honda Prelude 1990 H reg has covered only 64K. The alternator appears to be whining. Alternators can pack up at around 70K. The trouble with alternators is that they can fail without warning, usually at night when you need headlights. Why hasn't someone designed an alternator which incorporates more advanced warning to the driver of impending failure? Would it not be a good idea to replace the alternator as a matter of course at this mileage to prevent the dreaded red warning light syndrome at night? The whining noise I am told can be caused by a diode failure and the resulting voltage difference creating resonance. (or something like that). Should I make any checks?Voltage output check seems a bit simplistic. Anyone any ideas? Adam or J S perhaps? All the best, Mike
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Fri 19 Mar 2004 23:48
Whining Honda alternator - Civic8
They can pack up at anytime.the whining is normally bearings and wont mean its going to pack up.but doe`s give an indication that it is close to replacing.
diode failure would show up straight away or at least usualy doe`s.so may show up on the dash ie ignition bulb with a slight glow.apart from the whining any other problems?
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Sat 20 Mar 2004 09:10
Whining Honda alternator - Mikey Jay
No other problems with the alternator Mech1. Had the cambelt changed as a precaution as I did not know when it was last done. The old one was still as good as new! Almost certainly the original.
The slow running could be a bit smoother. I had better check timing etc. The vehicle will get much more use now. Thanks for replying.
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Sat 20 Mar 2004 21:06
Whining Honda alternator - kithmo
Alternators also hum when a diode is down, as well as the bearing being dry or worn, due to the imbalance of load. Regarding your more advanced alternator query, some of the new Ford range have a "smart" charging sytem whereby the Main ECU takes over the regulation of the charging system when the alternator fails, keeping the battery going but still illuminating the battery light to warn that it is this mode.
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Sun 21 Mar 2004 21:46
Whining Honda alternator - sierraman
Have you checked the belt tension?If too tight it will put a sideload on the front bearing causing premature failure.If you can do without the car for a day take the alt.off and have it over hauled by an autoelectrician.They will test all the electrical and mechanical components,replacing where needed.Last one I did cost £26.
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Tue 23 Mar 2004 20:52
Whining Honda alternator - Mikey Jay
Thanks for your replies. Could be an idea Sierraman.
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