Gtv alternator

[marktim]

Ok, I know everyone is going to say God not another question about 1982 gtv alternators  but yes i have need of some advice, my Bosch alternator was recently rebuilt and is in good condition, the auto lecky has tested it to 75amps,but when both my electric fans come on the revs drop significantly to where it is close to stalling and I've got it idling at about  950 to 1000,also the headlights are pretty ordinary but the high beam is pretty good, it's got solenoids on the starter and headlights and fans, any advice or information gladly accepted, cheers.

[marktim]

I said solenoids but meant relays  , got tired when I put the post on.

[Duk]

This is because old alternators can't deliver much current at low speed, regardless of what their maximum rated current is. This is a function of their design.

Look at using an alternator that was fitted to something a lot newer than the Alfa.
And naturally, make sure the earth points are clean and substantial.

[GTVeloce]

Realistically, look at the whole electrical system. Make sure the battery terminals are clean and tight. Run a new, much thicker (4 or 8 gauge) cable from the starter to the junction point near the alternator (careful you make sure it is well insulated and won't rub on anything). Create a new cable (similar gauge) from that junction block to the alternator. Run a new cable from the engine to a clean earth point and check all other earth points. Finally, put a relay on your ignition switch. It will save your switch and improve almost everything not currently relayed separately.

It is a bit of work but not that hard. Probably cost around $100 or so from Jaycar for the cabling and connections and you will never look back.

Attached is a photo showing the engine earth strap, new alternator cable (including green field cable) and the new battery earth cable (boot mounted battery) from my GTV. I ran a 65amp alternator and had no issues no matter what I threw at the electrical system.

[marktim]

Thanks for the suggestion, I cleaned and re attached all earth points today and will look at redoing the power lead from the battery to the junction box, everything from battery to alternator checks out fine, so it's something else causing the problem, cheers.

[105junior]

I was having what I thought was alternator issues with my Junior, so to rule it out I fitted the alternator out or my spider, the problem was still there, so checked all the wiring and cleaned all the connections, no cigar, so I cut off all the connectors at the battery and alternator and fitted new ones, problem solved and everything is nice and bright now.

[marktim]

I'll check that as well, thanks for the help, cheers.

[marktim]

Just a quick question about the twin electric fan set up in my gtv and the fact that when both fans come on the draw on the alternator is high, should both fans have a separate relay?, I can't find anything on the web about the wiring for this model in regards to the fan set up, if anyone has this  set up your advice would be greatly appreciated, cheers.

[marktim]

You were right one of the fan motors was running rough so I have replaced it with a new one, and I've found the cause of the large drop in revs when the fans turn on, it's the clutch engaging on the air-conditioning compressor, the compressor is a tcc brand, i believe American made unit.
When I had it recharged the guy couldn't believe the amount of gas it took, now I know that this unit was made for light trucks and when she turns on it takes a fair amount of revs to run it, I'm not sure if this compressor was standard but it's over kill, for this engine, in the end I've raised the idle to compensate for the load and the engine doesn't nearly stall when she kicks on, thanks for the replies much appreciated.