300Tdi had a stock 100A only the 200 had 65A, so unless someone else has been tinkering you already have the extra 35A in there.
Having said that, you can swap between the two and it is possible that someone has fitted one off a 200 as a "get by" solution.
Bigger is often better but as long as you have the cable capacity to get the current to the circuitry and battery then it's fine, the biggest stumbling block for would be tinkerers is the overlooked cable capacity, you can have all the amps in the world but if they can't get to where they are needed then they are useless.
Goc3k
Well-Known Member
You wont cook the battery with bigger (especially only marginally bigger), output is relative on an alternator as well - best comparison is seeing what they put out at engine idle.
Some of the cheap "120" amp alternators are just recon 100amp originals with a pulley swap, and the higher amperage is a factor of the pulley overdrive and the output being measured above the max engine speed of a 300tdi - though there is a lot more to the insides of a good alternator , no doubt someone will give you a good explanation or link somewhere that does
The denso one will be fine, as dieseldog pointed out it is the original output size.
and as an extra, I bought a britpart "new" 120 amp alternator 2 years ago and it puts out 15ish~amps at 800rpm according the the rebuild sheet that came with it, not actually enough for lights, wipers and blower on a cold wet night.
Some of the cheap "120" amp alternators are just recon 100amp originals with a pulley swap, and the higher amperage is a factor of the pulley overdrive and the output being measured above the max engine speed of a 300tdi - though there is a lot more to the insides of a good alternator , no doubt someone will give you a good explanation or link somewhere that does
The denso one will be fine, as dieseldog pointed out it is the original output size.
and as an extra, I bought a britpart "new" 120 amp alternator 2 years ago and it puts out 15ish~amps at 800rpm according the the rebuild sheet that came with it, not actually enough for lights, wipers and blower on a cold wet night.
discool
Well-Known Member
There’s no down sides, unless u have you have items fitted that will require that capacity from an alternator to replenish your battery/s.
As for the two LRs I’ve owned my 1987 RR alternator was around 64amp, now my 1997 disco the alternator is rated at 100amp, so possibly due to the electric heated seats, AC and heated front screen, as that’s the only difference in the electrics between the two vehicles.
As for the two LRs I’ve owned my 1987 RR alternator was around 64amp, now my 1997 disco the alternator is rated at 100amp, so possibly due to the electric heated seats, AC and heated front screen, as that’s the only difference in the electrics between the two vehicles.
Ah I thought the defender 300tdis were 65amp too, but the disco 300’s were 100.
My battery gets charge, but max voltage is about 12.9, 13 occasionally. So not enough to keep it topped up!
Re-wiring shouldn’t be an issue for me, but read somewhere that you need to regulate the voltage with 120 amp, but can’t find it again
My battery gets charge, but max voltage is about 12.9, 13 occasionally. So not enough to keep it topped up!
Re-wiring shouldn’t be an issue for me, but read somewhere that you need to regulate the voltage with 120 amp, but can’t find it again
discool
Well-Known Member
Off the cuff, I believe that the intro of the 300 for the disco vehicle it was fitted with the 100amp alternator, one alternator fits all, what ever the specification for the D1 was LRs logic at the time... maybe.
But the upgrade to a higher charging rate can be a beneficial depending on... etc etc.
But the upgrade to a higher charging rate can be a beneficial depending on... etc etc.
Hicap phill
Well-Known Member
A few V8efi were higher capacity’s.
discool
Well-Known Member
Ok, so what models and year would that be?
Remembering this thread is base on the 300tdi production years and standard factory specification.
I can only comment on the the D1 disco, ( i cant be bothered with info from my RR days) so the only alternators available in D1 time were, Lucas A127-65, A133-80, A127-85 and A127-100 all were available for both diesel and petrol, as LR felt necessary to fit.
Hicap phill
Well-Known Member
It was on a G plate classic RR.
On the rear of the alt was a 6mm thread to connect the main power to,
Now this may be a problem... my motor regularly had parts for testing BUT they would be for LR. Only motor due out would be a disco D1.
so Non serpentine.
I’m off for a search of alt
On the rear of the alt was a 6mm thread to connect the main power to,
Now this may be a problem... my motor regularly had parts for testing BUT they would be for LR. Only motor due out would be a disco D1.
so Non serpentine.
I’m off for a search of alt
