| Author | Message | ||
| Warren E. Smith (Magoo)
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I'm certain Herbert is correct. The symptoms sound like that to me. Electrical parts are like a light bulb. Works great when it's on. But then it goes out. When? Anybodys guess. MAGOO | ||
| James Pai (Jaymus)
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Herbert, thank for you all the help. It's not I am not taking your advise. It's just wierd that a rebuilt alternator would fail so fast, I guess it did. I'll just get my mechanic to replace it or take it back to the shop to see what happend. Thanks, Herbert. All you guys' advise is always welcome, I am just very mechanically challenged and just wonder why a part that was recently replace/rebuilt failed so fast. Thanks all James | ||
| Herbert E. Gault (Irfgt)
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Bingo!!! Any time you increase the power you sacrifice longevity. This also blows the theory of Ferraris being detuned race engines. If that were the case then they should last forever. Any way back to the discussion. I do not fool with increasing the power because when I do something, I warranty it, and if you are working on a design that is marginal to start with, then you are asking for trouble. The problem with alternators today is that they are adding more power and lighter weight and in a cramped quarters with little cooling and you end up with electrical failure. any electrical component is subject to failure especially early in it's life. If it ain't broke then don't fix it. | ||
| Ben Lobenstein 90 TR (Benjet)
|
James - While I was going to post something about HotRodded alternators (which I really shouldn't do, since I know so very little about them), I will say that there aren't many components to the charging system here (dare I say parts, then Herbert would tell me there are lots of parts IN the alternator, hehehe). I would have to say if you are having ANY charging issuses (idiot light on, battery dying, etc. and/or noises from the alternator), then there isn't too much else it could be other than the alternator gone bad, in some form or fashion. Just because it's been rebuilt recently (espcially if you had it HotRodded/upgraded) doesn't mean it hasn't taken a crap. Ok now I guess I wil share my thoughts on HotRodded/upgraded Alternators... Herbert - PLEASE TELL ME IF THIS IS INCORRECT!!! (While I do have a conceptual understanding of alternators I do not know them on the component level as you do Herbert, so tell me if I am putting my foot in my mouth here. You seem to deal with them on a dialy basis. I don't want to give incorrect/bad advice.) When I recently had my alternator out I took it to several local alternator specialty shops (automotive electrical places) they all told me it (HotRodding/Upgading) can be done but all strongly recomended that I do NOT do it. The explanaiton went like this: If you want to take a (i.e.) 100amp alt and bump it to 150amp you will have to give up something in order to get something. They went on to say that if you want more output at idle you give up more output at high RPM's or if you want more output at high RPM's you give up quite a bit of output at idle. Right now as stock they are doing exactly what they are designed to do. Modifing the alt could lead to more problems than it solves. Did they say this just because they didn't want to do it? not experienced? or maybe for liability reasons? or they just have so many HotRodded ones that come back needing further repair? I know I have seen and heard of it being done, so what's the deal? Herbert was this all a load of bull? I chose to leave mine the way it was, if it's working why mess with it? -Ben | ||
| Herbert E. Gault (Irfgt)
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I give up. It is obvious that I cannot convince you that you have a bad alternator. If you are not willing to heed advice then why ask? | ||
| James Pai (Jaymus)
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Thanks for the input guys. Herbert, my alternator was rebuilt just maybe under a month ago. It DID make the noisy bearing sound prior to the rebuilt. Now, the problem is that I get get the "battery warning light" on (very dim) at difference range/RPM underload. At higher revs/gear the light goes dimmer and dimmer, but at idle it's on more pronounced. Not bright, but noticeable. I'll check the battery as suggested by Erik, and post more updates. I love this forum, so much knowledge sharing and people are always willing to help! Thanks James Oh yea, so Herbert, if the system is charging why do you think my light is on? Can you help on that? Please give me more feedback and details. | ||
| Herbert E. Gault (Irfgt)
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A multimeter will not necessarily diagnose your alternator problem. As I said earlier, a failed diode will cause a noise but will not always cause a decline in the charging voltage that you will read on a meter. I repair alternators every day that are charging just fine but the light is on and it makes a noise like a bad bearing. | ||
| Erik Jonsson (Gamester)
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Black lead is negative, Red lead is positive. Attach red lead to + Terminal of battery, - lead to chassis or neg batt cable. The ohms reading is used to test for shorts and resistance. The DC A is Direct current amps, you use this to test current draw in a circuit(tester is inserted inline) and is only used for small items like the current a small light bulb draws. The DC V is Direct current volts. This is what you will be using to verify if the battery is charging, and the voltage of the battery when the car is off. When the car is off you should see a voltage of 12.6 or more. When the car is running and the alternator is producing a charge, this should read between 13.6 and 14 volts DC. The AC V setting is for alternating current(the type you have in your home. If you were to set it to this and insert the probes in an outlet, you should see a reading of about 118 to 121 Volts AC. The only thing I can think BATTV might be is to test the battery in the mutlimeter itself. Hope I have helped. Erik | ||
| James Pai (Jaymus)
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Hi, can someone enlighten me on how to check the battery/alternator/charging system to see what's wrong with my 90TR (See my other post on Battery Warning light dim) Steve on the forum suggest it's probably my rectifier bridge or some diode on my alternator. My mechanic told me if I had a multitester, he can guide me on how to check the charging system. I am mechanically challenged  Can someone fill me in on all the settings for the multitester? (like what OHMS, DCA or DCV, or BATTV, ACV etc. What setting should I be using, and what leads I should be touching to what! Thanks you all in advance!!! James |