Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: robson on 25 September 2014, 09:26:23
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I recently had a new alternator put on my 2,6 It gets very hot is this normal. I have never checked this before and have only checked on this new one because of the smell of hot electics in the engine bay.
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in my humble opinion heat equals resistance and the smell of hot electrics certainly in the vicinity of an alternator gives me enough hebe geebies to warrant further inspection by someone far more experienced than I !!
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As I didnt get much response to my post I am trying again My new alternator still gets very hot and an electrical smell is evident after a run. Should I be worried or is it newness working off.I also get an oily deposit on the air intake tubes,
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The thing is, the alternator is in good thermal contact with the engine block, and that certainly gets hot. If you can detect considerable heat output from the alternator after a short run while the engine is still cold, then I'd say that's unusual, but once the engine is hot, so will the alternator be, regardless of whether it's generating an abnormal amount of heat.
Have you checked that the alternator is producing the correct electrical output, for a start?
http://www.omegaowners.com/forum/index.php?topic=90619.0 (http://www.omegaowners.com/forum/index.php?topic=90619.0)
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I would expect the alternator to be pretty warm but not hot, the setup has a shaft mounted cooling fan so is pretty well ventilated with the engine running.
does it get hot with the ignition on but engine not running (e.g. with a cold engine)?
Also as per Kevin's advice, check the output volts.
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Thanks for the replies, The alternator is cold before starting the engine. Voltage readings are battery 12.4 after leaving overnight. Alternater voltage at battery 900 rpm 14.8 2000 rpm 14.75. A little high maybe?
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sounds normal to me.. Could the battery be so bad or some device eating a lot electricity in car so the alternator has to work on full steam all the time?
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14.8 is on the high side, but not worryingly so IMHO. Does the voltage rise higher after the engine has been running for a while and the battery is fully charged? Might be worth checking it after a journey, before stopping the engine. Also, load up the electrical system with heated window & seats, headlights, blower on full and so on, and see how the voltage holds up then. If the alternator is faulty, I'd be surprised if it doesn't drop once a full load is presented to it
Whilst it's possible that something is causing an abnormal load, there isn't much that will do so yet not also flatten the battery in short order when the engine is stopped, IMHO.
The most likely scenario for an alternator that's getting excessively hot yet, from the outside, appears to be working perfectly would probably be a shorted turn or two in the stator windings or perhaps a diode in the rectifier pack that has failed short circuit.
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Thanks Kevin will check after run tomorrow. :y
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Yep, shorted rectifier diode is the usual :y
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the point which interested me, was the reference to the hot electrics smell in the engine bay, having been driving now for approx. 40yrs in and on a variety of vehicles, I for the life of me cannot remember an alternator in good condition smelling to the point that it becomes noticeable. however i'm as always, open to suggestions as to why this particular unit should smell stronger than most.
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My feelings exactly cnj I have never come across this before.
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the point which interested me, was the reference to the hot electrics smell in the engine bay, having been driving now for approx. 40yrs in and on a variety of vehicles, I for the life of me cannot remember an alternator in good condition smelling to the point that it becomes noticeable. however i'm as always, open to suggestions as to why this particular unit should smell stronger than most.
Yes that's not right imo. I've fitted a couple of new alternators on omegas and never had a noticable smell of burning after.
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I can imagine you might get a smell the first few times it gets hot, but agreed, a smell is worrying. You'll get a smell of hot varnish if the windings are overheating, as that's what the wire is insulated with.
Not much you can really do without removing it from the car. Might be worth inspecting it to see if any of the stator windings show any sign of scorching. If it's a diode you'll find some of the windings have been running hotter than others, so you can spot the difference in colour of the varnish.
You can spot a diode failure by looking at the current waveform at the output, but that requires an oscilloscope.
If it's new, can you remove it and ask the supplier to test it? Difficult if it's not showing any symptoms other than a smell and is otherwise working fine, though. :-\
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I will be doing further voltage checks and I have booked the car into the garage that obtained and fitted the alternator on friday. Up to now they just scratch their heads and say they think all is well. Will keep you posted.
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Thanks for the replies, The alternator is cold before starting the engine. Voltage readings are battery 12.4 after leaving overnight. Alternater voltage at battery 900 rpm 14.8 2000 rpm 14.75. A little high maybe?
I'm getting around 12.3 and 14.4......which I believe is in the 'normal range'
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Thanks for those figures hopefully will resolve on friday
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I havnt had time to check my alternator under load but I took the car back to the garage today and they say that the alternator was not charging under load. We all knew that there was something wrong with it. Another new one being fitted under guarantee :y
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Garage fitted new alternator under guarantee. They said that towing my caravan had overloaded the previous alternator. Any comments?
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Garage fitted new alternator under guarantee. They said that towing my caravan had overloaded the previous alternator. Any comments?
Bolleeeeeerx ;D
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Hello Chris You will have to explain that one. ???
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Hello Chris You will have to explain that one. ???
Towing a caravan should not fry an alternator. It's faulty. Or they fitted the wrong one.
There for they are talking......
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Thats what I thought Chris I have been towing for 15 yrs without any alternator problems,
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bullshit stinks. absolute bullshit stinks absolutely !!!