1955 Buick - Generator to alternator conversion wiring question

[Ttotired]

22 hours ago, Beemon said:

When you compare numbers, the cost to install an alternator is dwarfed by buying a new voltage regulator by $20. If your voltage regulator fries, then you have other issues within the generator that may also need to be looked at and a rebuild can run up to almost $100 in some cases. Alternators are also solid state voltage regulation, so there's no fear of burning points out. Lastly, there are many models ranging from the stock 30 amps all the way up to 120 amps, which broadens what you can put on the car and feel safe running (electric radiator fan, solid state ignition system, EFI, modern AC, sound system).

 

I tried the alternator conversion, worked really well, except I used a Mopar alternator (they flow/look better than a GM, but mount differently - where I screwed up). The Mopar alternator is triggered through the amp meter in the dash, so keeping the wiring the same meant I could do without a dummy light. I eventually removed it, though, because it didn't look right sitting there and the custom bracket to mount it was flimsy - not in construction, but the fact there there were two flex points to mount instead of one led to some very interesting scenarios. I had also wired it into the starter relay from the 6v field terminals and my starter relay welded shut and blew my starter, so I removed the whole system and went back to stock...

 

If I were to do an alternator conversion again, I would spend the money on the Powermaster alternator. Some units come with a field "lamp" terminal, which gives off 6V when charging to use as a ground for the starter relay. Of course the issue with one wire alternators is that you have to put your foot into them to get them to charge, and the old Buicks are turned over by putting your foot into it. Buick5563 has never had an issue, so it's probably nothing to worry about. Curious to know at what RPM they kick in at, though.

 

 

With the description you just gave, I can now see why you have had those electrical problems

 

The 6v tapping on an alternator (If it has one) is actually a 12v a/c signal (shows 6v on a dc volt meter) and is used for running a tachometer (trucks with caterpillar engines are one that do this) or an electric choke signal (ford did this for a while), but, it is not a field anything, its taken from the stator. Because its a/c, if you apply it to a coil, like in a relay, the contacts will "buzz" (as in, open, close, open, close) with every alternation of the voltage.

Not sure which mopar alternator you were using, but the external reg type use ignition via the regulator to work and the internal reg ones needed the warning light to kick the alternator off, but an amp meter doesnt kick anything off

Most alternators do have a warning light signal wire, some its just a reference voltage (1 wire systems) others, its used to excite (trigger) the alternator, this is a 12v dc output when the alternator is charging, but is not designed to carry much more load than a 3W bulb, so if your trying to use it as an "engine running reference" I would put it through a relay first

 

 

[john compono]

I have a 55 Buick century and was wondering should I replace the generator with an alternator ? its 12 volt already, but want to put a better sound system in it. can I do it with the generator in ? 

[old-tank]

You have a 30 amp system. Calculate what the new system requires leaving enough for the other needs.