[Fatboy11]

Hi

I,ve currently got a problem with my alternator, the alternator is fairly new (this year by previous owner).

I went out laning last Sunday and it appeared to be OK until the end of the day when I tried to start it and the battery was totally dead (battery only a few weeks old).
I have checked the voltage & continuity on the wiring going to it as per advice from another thread and they seem to be OK.

I have also tried giving it a bit of "gentle" persuasion with the mallet.

Can an alternator just pack up when only a few months old ?

Is there anyway it can get gunked up inside or are they well sealed ?

Any tests I can do to the actual alternator itself to check it ?

If I need a new alternator are there different ones (higher amps) I should be looking at ? It's for a 2.5na.

Cheers

Cheers.

 

[wickford90]

firstly did you drive through any deep ****e. yes they can just pack up its a land rover. yes you can get higher amp one ( i believe). any warning lights on. yes you can check them, but dont ask me how because i aint up on that weird electric stuff.

 

[pressbrake]

just check the running voltage which should be around 13-14v ish if not then its not making power

 

[blue beasty]

Mine packed up with no warning light.......something to do with an internal short

Easiest way to check is voltage at battery, should read 14+ volts with the engine running and yes you can get different specs............got a marine grade one on mine cause I got a mate that works for a marine engine company

 

[andy mcd]

If you are getting 14 volts or more at the battery with the engine running then the alternator isnt the problem>

Some motor factors can check your alternator for you.

I have had the cheap craddocks own brand alternator pack up on me before after a few months so i always buy OE ones now.

If it happened after playing in the mud you need to check all of your vehicles earths, Connection at the starter motor including the supply from the alternator.

What about the battery ? could that just be knackered ?

There isnt really any need to upgrade an alternator. i run spot light and winch from my two batteries with just a standard alternator and i havent had any probs.

Check the voltage across the battery with the engine running and give it a rev to see how much juice is being produced. Then we can sort it from there

 

[Fatboy11]

I did drive through the deep ****e but no warning lights.

13-14v is that at idling or at a certain rpm ?

I checked the battery voltage after charging it and it was 13.3v, it went down to 12.6v after starting the engine but didn't go much higher afterwards ( maybe gragually creeping up)
Can't believe it's knackered after a few months.

 

[andy mcd]

hoping for 14v with a rev. It shouldnt go higher than 14.4v cos of the regulator.
If you arnt getting above 12.6 volts then either the alternator or the witring is knackered

 

[blue beasty]

With it running the voltage your measuring isn't whats stored in the battery but the output from the alt (if its greater) and it should happily pump out 14v at tickover........so yes, believe it

 

[The Mad Hat Man]

Hi

I,ve currently got a problem with my alternator, the alternator is fairly new (this year by previous owner).

I went out laning last Sunday (that could be a clue - go thru any mud or water?) and it appeared to be OK until the end of the day when I tried to start it and the battery was totally dead (battery only a few weeks old).
I have checked the voltage & continuity on the wiring going to it as per advice from another thread and they seem to be OK. (what figures did yu get?)

I have also tried giving it a bit of "gentle" persuasion with the mallet. (wont do any good)

Can an alternator just pack up when only a few months old ? (yes)

Is there anyway it can get gunked up inside or are they well sealed ? (yes - easily - and no)

Any tests I can do to the actual alternator itself to check it ? (take it to Halfrauds or similarr - wont cost yu a penny, if yu can drive it there)

If I need a new alternator are there different ones (higher amps) I should be looking at ? It's for a 2.5na. (yes)

Cheers

Cheers.

there yare

a good alternator puts out 14.7 volts at about 2000 rpm.

 

[Fatboy11]

I don't think the person I bought it off would have fitted an OE part so guess it may be knackered then will double check voltage & continuity on wiring to alternator to be sure.

If I have to get an alternator any recommendations of new versus recon ?

Is there no chance that it could be a case of opening the alternator up and cleaning ?

Cheers

 

[andy mcd]

Sometime it is possible to replace the regulator and bush pack depending upon type of alternator> Personally i fit new ones OE as there only slightly dearer than a recon jobby

 

[Fatboy11]

Just seen rimmerbros do a recon exchange for £97, seems good to me as the cheapest I can find a new one is over £200.

 

[Fatboy11]

With all the wiring disconnected from the alternator should it still kick out 14v ish with the engine running/revving ?

Also it had 3 connector wires, 1 for the dashboard light and 2 heavier duty ones that go back to the battery I take it. Why 2 wires ?

Do the wires that come off the back of the starter motor go to anything else before going to the alternator ? Just seems like a long way to wire it around the engine block.

Cheers

 

[andy mcd]

the 2 wires from the back of the alternator run around to the + ve terminal on the starter. The alternator will not put out more than about 14.4 v even with the wiring disconnected as this is regulated by the regulator inside the alternator.


I only paid about £120 for an OE alternator and pulley for my 300TDI (brand new)

 

[Fatboy11]

the 2 wires from the back of the alternator run around to the + ve terminal on the starter. The alternator will not put out more than about 14.4 v even with the wiring disconnected as this is regulated by the regulator inside the alternator.


I only paid about £120 for an OE alternator and pulley for my 300TDI (brand new)

But it will still kick out 14.4v ish with the wires disconnected ?

Where did you get such a good deal on the alternator if you don't mind me asking ?

Cheers

 

[andy mcd]

Strangely enough it was a landrover parts company on ebay.
If the alternator is only producing 12 volts at the battery but 14.4 at theback of the alternaotr i would be checking the wiring between the alternator and starte, cleaning up the terminals on leads on the starter to see if that helps. Doesnt sound like an earth fault as you will be putting the neg lead from your multimeter on to the engine.

I used the cheap alternators in the past and only got a few thousand miles out of them

 

[Fatboy11]

Basically I'm only getting the battery voltage at the alternator connector with engine running and wiring connected.
When disconnecting the wiring from the alternator I get about 0.3v on alternator output when revving engine and nothing on idling.

Should I be getting 14v ish on alternator output with all wires disconnected ?

 

[The Mad Hat Man]

no
you need the battery light wire connected to trigger the alternator on.

 

[andy mcd]

when you remove the two wires ther should be 14.v volts from the out put of the battery.
Its a NA engine does it not have a plug ? i have had the internals of plugs corrode and melt away, could be worth checking this. some of the later models like the 300tdi use the battery warning light circuit to excite the alternator to get it to produce electricity pretty sure the NA doesnt.

 

[Fatboy11]

no
you need the battery light wire connected to trigger the alternator on.

Thanks will try that tomorrow.