Alfa Romeo Forums banner
1 - 6 of 6 Posts

·
Registered
Joined
·
401 Posts
Discussion Starter · #1 ·
Greetings, S-Men (and women);

I removed the alternator from my '73 to change the bearings and discovered the interior wiring in such a state that it needed much more attention than I was prepared to give it at that time (see pic 1; your old alternator, while perfect from the outside, might look just like this... just a thought :D). So I put in a spare alternator, started the rebuild and then forgot about it. Now I took it off the shelf, put it back together the way I thought I should, and arrived at the backside (see pic 2). Now, which wire goes where again?...
I made a pic prior to disengaging the wires (see pic 3). I thought it shall be enough, but I'm no longer sure. And of course, the spare alternator from a GTV - while it fits perfectly - is totally different in this regard. All my other alternators, too. No way to compare them. So I half-guessed at the solution (see pic4), does it look correct to you?
Additional questions:
- the left side B+ bolt was "capped" by a piece of plastic. Shall I cap the other B+ bolt too?
- There are slots for four very long and thin screws to hold the rear and front of the alternator together. However, I found only two; the other two slots were empty. Maybe the factory installed only two screws; maybe PO lost them somewhere... Shall I replace them?

Thanks for your input!
 

Attachments

·
Registered
Joined
·
401 Posts
Discussion Starter · #2 ·
Well, amidst all this huge blaze of no interest at all, I wired the rebuilt alternator the way pictured above and plugged it into an Alfetta GTV to give it a try. I was a bit scared of mechanical gremlins (bearing misalignment, rotating parts touching and so on) but mechanically it's just dandy and oh-so-perfect. Electrically, though, it doesn't do a damned thing, which is in stark contrast with the pre-rebuilt condition, when it produced mechanical noises but produced reasonable current as well. Now it's a mechanical dream without any current to speak of. Guess I'll have to dismantle it yet again and test everything I can. (Maybe I killed some diodes?)
 

·
Registered
Joined
·
2,045 Posts
Probably the reason for not much response is that this level of repair is beyond most owners. It is too easy to take the alternator to a local rebuilder or order one exchange and be pretty sure that you will receive a working replacement, even though it does take some $$ to get the deal done. The last rebuild on my 1988 alternator was $127.50. I have replaced a few (repeat few) bearings and regulators in the past, but normally take the rebuilt exchange route. I admire your interest and ingenuity in tackling a job of this magnitude, though.

Robert
1988 Black Spider Veloce
 

·
Registered
Joined
·
401 Posts
Discussion Starter · #4 ·
Thanks, but I have to admit that I shy away from even the simplest of tasks that involve ANYTHING inside the engine or the tranny. I compensate for that by taking apart everything else :D The reasons why I don't want to have my alty rebuilt are:
1. $$ - I have tons of other stuff I have to buy for the car, plus the alty is a rather old type; I doubt the local shops will have an exchange
2. I have pleny of alternators in perfect working order, but they are all for Alfettas, Milanos etc. Some of them fit perfectly, but they just don't look quite original. So the car ran fine, but the engine bay didn't look 100% to me; and if I choose to make my life harder by doing not-really-neccessary jobs, I might as well make my life REAL hard :D
However, this old type alternator - once I got its measure - is quite easy to take apart, you don't even have to touch the bearings (neither of them!). The regulator is a separate unit. According to the literature, you just have to be careful with the soldering; I'm afraid that's where I went wrong (overheated the diodes). I'll soon know; I did the dismantling yesterday and I want to check today.
 

·
Registered
Joined
·
401 Posts
Discussion Starter · #5 ·
Update: I had checked and cleaned everything and re-rewired some points. I had found at least one major short. I re-packaged the alty, installed it into the Alfetta GTV again, took it out, installed the belt pulley for even better results, plugged it in again then let her rip.
Lo and behold, it produced current!!!
Well, even more than I anticipated. Over 18 volts. It was the same with three different voltage regulators. Now either all three are defective (all three were OK before) or something weird is happening. The Alfetta is a '79 year 2000 and the alternator is for a '73 Spider 1600, but I had no trouble using the 'Fetta alternator in the Spider. Why isn't it working the other way around?
 

·
Registered
Joined
·
2,045 Posts
The Alfetta alternator is internally regulated, is it not? The 1600 unit is externally regulated, is it not? Therefore it would seem there is a wireing hook up discrepancy, or all 3 of the external regulators are defective (statistically highly unlikely).

Robert
 
1 - 6 of 6 Posts
Top