alternator help

I have already done a search and not come up with anything usefull.

basically I want to be upgrading my alternator on my 200tdi disco I forgot to check the current ampage fitted and its now dark so I will check it tomorrow but I have found 120amp ones for a 200tdi on ebay and 100 amp ones for a 300tdi aswell. I'm aware that I will need to be changing the pulley on a 300tdi one but is there any other modifications needed to upgrade my alternator. I'm thinking along the lines of heavier cabling, bigger battery?

surely someone has upgraded their alternator and has some advice

Pretty simple mate, bolt it on, make sure the supply cable to the battery is sufficient, or, run another direct to battery if you're not keen on disturbing existing wiring.

Only thing I guessed (still run 70amp V belt on my v8) is that high output alternators might slip heavily on V belt as opposed to poly-V, but you'll have to suck that one and see.

ok cheers. what do you mean by poly-V? same sort of thing as poly-bush? or am I just being stupid now?

Animal88 said:

ok cheers. what do you mean by poly-V? same sort of thing as poly-bush? or am I just being stupid now?

Click to expand...

poly v belt is multi v belt as in 200tdi uses single v 300tdi uses poly v ancillary belt

To simplify; V belt is definately V shaped and the other is not but has grooves running through the belt! 😊

V belt looks like "V" narrow and old fashioned

Poly V looks like "vvvvv" wide flat and modern

Poly v can supply more torque

ah ok i know them as ribbed or multi-v or serpentine belts. never heard of them being called poly-v's before

Tomato tomato

next problem guys I've been a tit and not taken a pic before I took the wires off the back of my alternator and now can't seem to remember how they go back has anyone got a pic of the wires on the alternator of a 200tdi disco engine

Big one is big one, what are the other two marked as?

i have a big brown one going to 'B+' then I have two other terminals on the alternator 'W' and 'D+' and I have a brown and yellow wire, a white wire and a red. the red sits outside the cable wrap of the other wires, i have traced it back to the bulkhead where it goes through a grommet and bulkhead to behind the dash.

could it be this red that is confusing me cos my haynes book is stating the brown yellow wire goes to the d+ but i can't remember where the white went but remembered the red being on the W.

I'll get a pic so it can make it clearer in about 10 mins

Plenty of pics online failing that I'm thinking d+ is brown/yellow exciter and w is rpm, not certain on colour though!

seem to have sorted it now got rid of the red as it seemed to be an add on from a previous owner that i need to trace and find what its for.

D+ is brown yellow
B+ is big brown
W is white

cheers for the help guys next is to trace the red and find out why I haven't got any horns

right next problem is even with the improvement in charge with the new 65amp alternator my truck still struggles for charge with the headlights on and either/or indicators or brakelights and nothing else. I have had this issue with my novavan and found it to be the charge relay is there anything like this on a 200tdi discovery? and where is it located? and does anyone know of a part number likely to be on the relay housing to help locate it

Not to my knowledge

200 discos are pretty simple BUT mine is a 3.5 and I've more or less established they are wired differently, I think mine is a RRC loom essentially

Check obvious things like follow alternator cable and check along it's route

Check engine earth points etc

I know with some vauxhalls you can 'assist' the alternator by putting an earth strap to the tensioner bolt of the alt and then to the block or chassis could this help my trucks alt cos surely a more direct earth for the alt would be better instead of having to go through the engine and then to the chassis via the engine earth

or am i just talking bs

the only reason i'm asking about a relay is that once started my alt only half charges for a few seconds then i get a click like a big relay then it jumps to full charge untill i turn anything on

Is the alternator itself known good?

Fairly certain these didn't have a charging relay of any description

Regards earthing, it's only if your engine is currently badly earthed but then it wouldn't start either

check you have ignition feed at the wire when disconnected at d+ igntion on ,check you have 12v at b+reconnect d+ and start engine read what volts at the battery now or b+ needs to be over 13v to charge

the alternator is a new one and it's charging better than my old one just not enough to run headlights and indicators which to me seems like it's not enough I'd expect it to struggle with extra lights or extra electrics. but seen as the headlights are standard and so are the indicators surely the standard 65amp alternator should be up to full charge with standard electric items being used.

I'll have to test the alternator and may have to renew and clean the earth strap and connection points. the only starting problem i have is first start of the day it's a little sluggish to start but has never failed yet