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Alternator Problems


Jon W

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My altenator is playing around at the moment. Looking at the voltmeter it is very near the 15V almost into the red and seems to be moving around more than it has been before. i.e. love voltage below 12V mark and the sometime normal sometime higher than normal.

I just checked the voltage across the battery with the engine running and it is 14.5 which is ok but when the engine speed is increased the voltage increased to 15.6 - 15.8 :blink: . Which obviously isn't right?? I suspect it maybe the earth. What to look for when re earthing, scrap paint away to get good contact, but i dont want to increase the chance of any more chassis rust.

Suggestions please

Jon

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My altenator is playing around at the moment. Looking at the voltmeter it is very near the 15V almost into the red and seems to be moving around more than it has been before. i.e. love voltage below 12V mark and the sometime normal sometime higher than normal.

I just checked the voltage across the battery with the engine running and it is 14.5 which is ok but when the engine speed is increased the voltage increased to 15.6 - 15.8 :blink: . Which obviously isn't right?? I suspect it maybe the earth. What to look for when re earthing, scrap paint away to get good contact, but i dont want to increase the chance of any more chassis rust.

Suggestions please

Jon

check your battery to alternator earth path, if that's good, your regulator pack has gone the way of the dodo

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Oh dam, knew it would probably be worse than i had expected, ill check the earths anyway. Where abouts is the regulator pack then and is it easy to change. I have had the alternator apart before but only to take the brushes out to clean mud od is it as easy as cleaning these???

Thanks

Jon

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on most lucas ones its a plastic moulding attached to the back end cap secured with 2 screws, it takes up about a quarter of the back end, sure someone will post a pic on here. The brushes are integral to it, remove the screws and it will slide out, u can then clean the slip rings with meths. You shouldn't need to dismantle the alternator. If you have a 200/300Tdi lucas alt I can send u a reg for a tenner as I have several new ones.

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I think its a lucas alternator but it for a 2.5 petrol i will go and have a look. I know it is an alternator with a black cap on the back with 2 screws which can be removed to enable the brushes to be removed and cleaned. I will go and have a look and see what else i can find.

Cheers

Jon

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ok thats an earlier type, regulator is different but should be obvoius, the brush connections will go to it. The output winding goes to the diode pack which is a different part of the alt.

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Well he's taken it to a local alternator place and they've said the regulator is dead, along wth diodes and maybe a few other bits. Replacement alternators seem cheap - can get an 85 amp one for less than £50 but will the wire from it to the battery need to be upgraded? I think the one on there is 45amp at the moment, and I don't want wires going up in smoke!

Richard

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Cheers for the offer Jon but have brought a replacement now as need the truck tomorrow. The price seemed good and the bloke seemed to know what he was talking about which was good. He said it wont charge at 85 Amps if the wiring is not up to it but it should be fine to run it with out any problems. I will up rate the wiring when i can so that it does charge at 85 amps.

Thanks to every for their help. Just got to go an fit it not in the dark and rain, don't you just love land rovers at times

Jon

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Ok replacement is the reverse of taking apart except fir i have forgotten which bits go where. Basically there is a nut and bolt and 1 washer per bolt. So where does the washer go bolt head end? between the alternator and engine block or between the nut and alternator. i doubt any of that makes sense but here a ppicture to paint a 100 words.

Alt.jpg

Just checking it goes the right way round for electricl conductivity etc.

Cheers Jon

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Yer i thought it was like that but the bloke at the alternator shop said it looked like something had been going on by the alternator to engine block mount, and so to clean it up for good contact so didnt know whether washers were needed there.

Thanks

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Right all fixed now and seems to be charging alright.

James not too far ???? Its about 200miles from me as i'm in sussex. Its not too far from darth but he only has the rover 200 at the moment so maybe on bitching duty.

I would like to come down for it but its around exam time so i can't make it and its a long way for a day. Will be at steve's challenge at easter though. So may see you there.

Cheers

Jon

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200miles is nothing, fill up before you leave, keep below 80mph and there shoudl be enough fuel for the event then just fill to go home. so 2 tanks fo fuel cant be that far.........................................

fair one i thought you were both in Exeter

Exams - i shouldnt worry too much about them, they will be there next year..........

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If only i could get to exeter do an event on one tank, it would be bliss. But unfortuneately i can get to exeter on 1 tank and have fumes left in the tank. Exams are quite important so that i get a uni place next year for veterinary, but would much rather do an event than revision but needs must as they say.

See you again soon.

Jon

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Cheers for the offer Jon but have brought a replacement now as need the truck tomorrow. The price seemed good and the bloke seemed to know what he was talking about which was good. He said it wont charge at 85 Amps if the wiring is not up to it but it should be fine to run it with out any problems. I will up rate the wiring when i can so that it does charge at 85 amps.

Thanks to every for their help. Just got to go an fit it not in the dark and rain, don't you just love land rovers at times

Jon

Absolute rubbish!!!!

If you put enough load through it to draw 85 amps, the alternator will provide 85 amps. If the wiring aint up to it it'll just melt, plain and simple!!! You can draw 500amps through a 0.5mm cable if you try, but it'll get bluddy hot bluddy quickly!!!

Change the wiring ASAFP casue melty wires is scary and expensive!

Jon

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If you put enough load through it to draw 85 amps, the alternator will provide 85 amps. If the wiring aint up to it it'll just melt, plain and simple!!! You can draw 500amps through a 0.5mm cable if you try, but it'll get bluddy hot bluddy quickly!!!

Change the wiring ASAFP casue melty wires is scary and expensive!

Jon

Ah, so as long as the load on the electrical system isn't put under any huge strain (eg. electric winch) then it will be fine? Only got headlights and the heater to worry about, which was fine with the 45amp one so the load shouldn't be any higher than that?

Obviously the wiring to the battery will be changed soon but it'll be okay for now?

Richard

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Heater on, rear screen heater on, wipers on, lights on, stereo on full blast etc. Plus if the batterys a bit low casue you've left the lights on or you had to crank it for a good few seconds to get it started the alternator will soon go to full output to top the battery up. The std 45 amp jobbie is barely up to keeping the battery topped up with everything on.

DONT BUGGER ABOUT GET IT CHANGED!!!!!!!!!!!

Its only the wiring from the alternator to the starter solenoid anyway. Bear in mind that if it does melt there is no way to isolate this wiring. Its permanently live to the battery, there are no fuses, there are no switches, its landrover up in smoke time, and trust me you do not want to be panicing trying to pull red hot wiring off with your bare fingers.

GET IT CHANGED!!!!!!!

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Cheers Jon,

So is it just the wire from the alternator to the starter solonoid that needs changing? Everything else is fine as normal?

Do later vehicles with larger alternators have a thicker wire here to cope (and anywhere else), and has anyone got a part number for it?

Richard

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Yes - the thick brown wire runs from the alternator to the starter solenoid. From there its in thick cable back to the battery.

Buying landrover parts will cost you a fortune. Get onto vehicle wiring products and get the correct spec cable and either ring terminals, or the correct lucas plug depending on what your alternator needs. (they do the lucas alternator plugs if required.

In short, yes if a vehicle was fitted with a higher output alternator it will have had thicker wiring. However I strongly suspect the 2.5 petrol only came with a 45 amp alternator. The engine loom comes as a complete assembly and can simply be unplugged and removed from the engine (this includes the alternator wiring down to the solenoid). I suggest you undo and remove the loom, untape it all and replace the wire concerned (be prepared there will be more than one thick brown wire in the loom so only replace the right one). Then re-tape it all up and re-fit to the vehicel. Job done.

The whole lot should cost you less than a tenner. At least then you know its safe no matter what.

Jon

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DONT BUGGER ABOUT GET IT CHANGED!!!!!!!!!!!

You beat me to that comment! when I read on the previous page what the salesman said I automatically thought tw@t.

As has been stated, an alternator works on the basis that it will supply what it see's is demanded, until it reaches it's maximum capability, if it senses 2A is required, it produces about that, if it see's a heavy current draw is in presence, it will try and balance that current draw-out so that the battery isn't being drained.

In essence, the alternator don't give a hooley about your wiring, it's only interested in the load being shown to it.

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You beat me to that comment! when I read on the previous page what the salesman said I automatically thought tw@t.

agree with that man, the bloke in the shop don't know what he's on about. this is the most critical part of you vehicle electrical system, as the other guys said, no fuses, no second chances, if it goes wrong you get to hang out with firemen... ;)

you'll be able to change it in an hour or so........ :):D

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