New alternator not working . scirocco gt11

[njl1968]

Hi,
Just fitted a recon Bosch alternator 65amp from euro car parts . Started up no charge light on , thought good it’s working then checked voltage 12.5 and going down, so not working. Charge light now not working on ignition start up, it did with the old alternator. I have measured the voltage +pillar to the the battery and it’s the same as at the battery terminals. I then disconnected the +Pilar and measured accross to the alternator casing 0.85v . Am I missing something or do I have a dud alternator? Does the blue wire and charge light indicate a different issue?

Thanks njl1968

[unknownmale]

Have you checked voltage from Positive on the battery to the casing (checking the alternated has a good ground through the block. Assuming both wires are attached to the back of the alternator?

[njl1968]

Yep tested that voltage is the same as if I tested accross the battery near enough. Ground on the alternator is good , checked the voltage from the positive post to the negative and the B+terminal same as above. Also checked the blue wire continuity to a harness point at battery that’s fine. I am curious about the battery charge light not coming on , how is this controlled? I tried grounding the blue connector and Athens light does not come on. Anymore ideas welcome otherwise I willl take it back in the morning to exchange for another one.

[james butler]

check the connection somewhere near the battery positive terminal the blue wire has a join in the wire there.
you should have battery voltage there when the ignition is on
could be a loose connection or broken wire

[njl1968]

Ok checked I have volts on blue wire, also dismounted new alternator remounted old one red light comes with ignition. I thought new alternator must be faulty took it back just slotted in new one light does not come on , what the hell is going on is new one wrong part ? If it where the wrong amperage would this be the problem?

Cheers neil

[njl1968]

All fixed thanks for the responses, my problem, new alternator has a differnt connection ring rather than spade on the d post that the blue wire connects attaches to, there was another connector spade end connector which was an additional b+ post that I connected to , hence not it did not work. That’s the problem with with working in the dark in the evening.

Cheers neil