ALTERNATOR PROBLEM/COMPATIBILITY (does a 2.0/1.6 fit in a 1.8t)

[Dommy GTi]

My alternator on my golf 1.8t mk4 has gone...

My mate has 2 alternators at his crap yard, one for a 1.6 and another for a 2.0 gti 8v.

would the alternator be compatible with my car? ive seen on ebay that it says they are.
but nowadays you can't trust ebay. so would rather hear from guys on here that its able to work and i won't be wasting my money...

[jamie16v]

if he is your mate, you have both alternators, just compare them  if they are the same then they fit.
alternatively try and diagnose what`s wrong with yours and fix it. the rectifier went on mine last month, it was only £30 to fix.

[Dommy GTi]

cheers mate, basically, the battery light come out when i gave it some in 1st gear up to 6k revs  and then everytime the throttle was pushed, it would beep and say 'alternator workshop' but if you gave it a bit of boost it would turn off, then its light when its cooled down it would come back on again.

then next thing my battery died after a while, and the alternator didnt charge it at all? would it be what you have mentioned mate?

[Jin_C]

Also make sure they have at least the same amperage as your current one. It is ok if you go over but going under may cause issues.

[Wazzzer]

going over will blow the fuse on the top of the battery, make sure you get that as well if it's different

[Jin_C]

Really? I upgraded mine (90a to 120a) without changing any fuses and its been fine. Spoke to my dad who used to be an electrical engineer and he didn't mention it. Although he could have overlooked it.

[Dommy GTi]

so its worth buying the 2.0l 8v alternator? or the 1.6 16v? i cant find anywhere that would tell me if it would work which is a bastard 

[Wazzzer]

Really? I upgraded mine (90a to 120a) without changing any fuses and its been fine. Spoke to my dad who used to be an electrical engineer and he didn't mention it. Although he could have overlooked it.

Yes mate trace the power cable from the alternator to the battery and see what rating the fuse is in there. IIRC it should be 150a fuse if you have a 120a alternator. It may be that you never draw enough power to pop it as the 120a usually came on cars with heated seats, then as standard on the later mk4s