Alternator buzzing when car stopped?

[3sacrwd]

Here is a pic of the Hack Job.

 

[mangusta1969]

That is a serious hack job. What was someone thinking?

Glad you were able to hang in there with us. Everything is not always as it first appears to be.

 

[vettenick]

Good job! It really scares me what some "professionals" will do.
Chalk up another one for the good guys!

 

[vettenick]

I'd just like to bring something to everyone's attention regarding Gm's alternators. GM is all over the place when it comes to alternator wiring. They differ from year to year as well as model to model within a year. Don't assume that they are all interchangable. And what applies to one year may not mean that same thing applies to another. Just make sure that you have the correct wiring diagram before you touch anything.
Have a great holiday everyone!

Nick

 

[Galen]

What an excelent hack job just plain a thing of beauty did they use tape or just like the pic. I did a little test today to kinda match the hack job. I wired the 3 leads all dirsct to 12 volts possitive and grounded correctly. (not on a Vette of course) the alternator of course charged correctly but there was no way I could make it whine. It of course would drain the battery as there was a draw with that set up. I just cant understand the whine I have heard it before many times but always was the diodes bad. Having rebuilt many of that exact alternator I am baffled. I am amazed that it charged as well as it did. The regulator in that alternator is also very weak we used that type on all of our plow trucks back then and they would go thru regulators all the time. All I can say is glad you found that hack job. But you may have hurt the alternator feeding it power all the time if you can have them test it and see it even a little weak they may replace it and then you should be golden. Good luck.

Galen

 

[geekinavette]

Persistence pays off yet again!

Glad to hear you finally found the problem. Nice job!

Bill

 

[3sacrwd]

Thanks.....The wires were wrapped in a sort of cloth type tape, not electrical tape. I think there may have been a bit of a short going on in there. That picture is what it all looked like directly after I took the tape off. The whine was barely audible, you had to put your ear pretty close to the alt to hear it.....
Thanks again for all the help.

Kevin

 

[BrianD]

Alternator Buzzing Humming with engine and ingnition off

I have solved my humming/ Buzzing problem on a 2003 Volkswagen New Beetle 2.0 AVH GLS 2dr Hatchback . Humming was coming from the alternator, but I was not sure that it was caused my brand new Re-Manufactured alternator, as this new alt was putting out 14.38volts as it should, when the engine was running. But Alternator humming with the engine off and key out, was draining the brand new battery (02/16 WM MAXX 5yr) from 12.68v to 12.22 volts overnight. (tested over just one cool (say 45F) night.)

Took the Alt off and to local auto parts store to have checked out...It checked out as GOOD. However, they had not seen a humming Alt before. So we (me and five others) looked on as the boss used a jump start kit to energize the alt and it buzzed away. Also this caused the Non-Clutched pulley to not spin freely when energized, but smooth and free spinning when Not energized. The rectifier was suspect, but I believe that a diode soldered in place internally during RE-MANUFACTURING was/is the problem (part of the "Diode Trio".)

So I left parts store with a new $200 Ultima 90amp Alt. + $46 core and my Eb@y Re-man, $100 90amp, no-core chg, batt. killing, pos. The guys at the store did not rub it in about my bad online order.

External temp using inferred "laser" of the cheaper bad Alternator=165 F exterior housing and 205 F interior windings. New Ultima Alt = 75F exterior and 83F interior, all tested when engine running @ idle and block at 156F. Bad Alternator Running HOT and putting out 14.31 volts.

As a side note; The bolts on the back of the bad Alt were switched (longer one on B+2 instead of B+1) which it does not matter for power purposes (come from the exact same source/inner frame pwr block of alternator,) just getting the Battery wire to hook up was a stretch.

I testing the smaller two wires (called field and sensing wires) on both alternator's rectifiers (not from the cars wiring harness connector plugs, but on the Alternators plug socket themselves, alt installed on car and B+1 Cable to Batt Pos. connected) while installed on car, engine off, key out, doors closed. I was getting 11.67volts FIELD (with ignition OFF, Key out,That's BAD) and 4.42volts Sensing wire (Bad again) when the replaced alternator is now giving me 0.01volts Field and 12.33volts Sensing wire. The previous numbers have been reviewed, are correct and have not been transposed or mislabeled.


I know its a long post. It is my first post. I spent over a week thinking my issue was electrical shorts in wiring harness, relays, Pwr control Module (PCM) anything and everything BUT a NEWLY purchased and yet BAD ALTERNATOR. Very little online about the subject.

I hope this helps someone.

BD


Understanding Alternators. What is an Alternator and How Does It Work