PROCHARGED89Z

I tried to explain this in my other post.Seem like my altenator is making a slight buzzing noise when the igniton is off,over time like 20-30 min the case starts to get hot.WTF?Im stumped.My battery is in the trunk and the cable seems to get warm too.What can it be?insuffcient grounds or what?Help I dont want a fire.

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Check out my Hompage,or the beginnings of one.355 dynoed at 400HP at 5800RPM & 410LBFT of TQ,on Motorhttp://www.procharged89z.cz28.com/index.html

Stuart Moss

If I had to guess, I would say that you have a bad rectifier assembly in your alternator.

The voltage regulator could also be bad (e.g. an internal short to ground from the battery, or output post), but my first guess would be a bad rectifier with at least two bad diodes (there are a total of six).

If two diodes are reverse conducting passing current from the battery to a bad diode to a stator winding to another bad diode to ground, then I could understand why the alternator would get hot producing essentially a short-to-ground. The buzzing sound I can only imagine - perhaps a diode or two are not completely shorted (anode to cathode) and because of that, oscillating. To make a noise loud enough to hear, I'd imagine that a lot of current would be passing through the diodes, and this would be confirmed by the alternator getting hot when not operating.

Look into having it tested free at an major auto parts store and let us know what you find.

EDIT:
I forgot to ask. What happens after 20-30 minutes to cause the buzzing to stop? Does the battery drain so much that it cannot produce enough current keep up? Does the alternator then cool down? Have you noticed any loss of battery capacity (is it drained or hard to start the car)? After the 20-30 minutes after the buzzing stops, with the car still off, replace the battery with a fresh one. Now, if the buzzing and heat start again, you'll know that it stops because the battery has simply become drained.

With the car off (key out), a good, bad or even no ground to the alternator is unimportant. The only time you'll need a good ground to the alternator is when it is operating (engine "on").

[This message has been edited by Stuart Moss (edited July 24, 2001).]

PROCHARGED89Z

Stuart tHanks for responding again.First off the noise is almost not moticable but with the garage door closed and me listening carfully I hear it,so I put my ear to the altenator and there it is.What it is doing is I would connect the battery,and I was checking my connections for my gauges and stuff and after say 20 minutes I go and put my hand on the altenator,it seems warm,now this is without even running the car.CAble in the back of the car is warm too.I will be taking it to Autozone to have it checked out.Now that you mention it I was trying tio start my car the other day for the first time,put a new motor in it and was programing my tec 2.I had just bought a new Optima battery,It took maybe 20-30 crank overs and the battery quit.I had to put a small trickl e 2 amp chage on it all night for a fresh start the next day.So in your opinion,you think the altenator is bad.It sat for over a year and a half in a box in my garage and it is about 4 years old anyway.So something inside is shorting out.I ll keep you updated Im bringing it to Autozone today,it a lifetime warrenty altenator.

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Check out my Hompage,or the beginnings of one.355 dynoed at 400HP at 5800RPM & 410LBFT of TQ,on Motorhttp://www.procharged89z.cz28.com/index.html

Stuart Moss

Yea, definately have the alternator checked and let us know what you find (you got my curiosity up). And "no", an alternator will not, or perhaps I should say "should not" go bad by just sitting on a shelf unconnected to anything.

All the symptoms point to the alternator (probably the regulator and/or rectifier) being bad. The hum/buzzing sound, warm alternator case after the engine has cooled and warm output wire indicate that the alternator is drawing current, and quite a bit to heat up the alternator/output wire, after it as been "turned off" (via the ignition switch).

[This message has been edited by Stuart Moss (edited July 25, 2001).]

PROCHARGED89Z

Stuart,First off I want to thank you for your help.I took it into Autozone today to have it checked,it checked out fine .So I went back and went over my wiring again.And I found the problem.The little harness that plugs into the back of the altenator,well there is 2 wires comming out of it,the smaller one was hooked up directly to power .Boy am I stupid,I wired it up correctly,I looks threw then helms book,it is supposed to be hooked up to the D leg of the fan relays.With all this wiring this is bound to happen.Thanks Stuart.

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Check out my Hompage,or the beginnings of one.355 dynoed at 400HP at 5800RPM & 410LBFT of TQ,on Motorhttp://www.procharged89z.cz28.com/index.html