Having pics is a great help! thanks.
Agree with the others that you have a stock "style" of alternator, even though the original has obviously been replaced. As has the regulator, at least once.
And yes, that is your voltage regulator there on the firewall.
This type of alternator is capable of putting out more amperage if customized, but the typical range is 45 to 65 amps. Most modern ones are wired to put out about 65a though.
Agree with the others also, that the more modern, and higher output capable 3G is a nice upgrade for any Bronco. More so if you're running EFI of any kind.
Also the internal regulator does simplify wiring and clean up the engine compartment because you can get rid of your old one.
But there are other things at work here too possibly. Even with EFI your charging system should not be pulsing like that. You should check your wiring condition and grounds.
With all setups, but especially with EFI, you should make sure you have good grounds everywhere. Battery to body, battery to engine block, engine block to body, etc...
The one downside to the more powerful alternators is belt squeal. A couple of simple cures are available, depending on how your rig is set up and what you like to do.
A larger diameter pulley on the alternator will help by giving your belt more grip.
A dual-sheave pulley will help by the same fashion, but a little more effectively perhaps. But you have to have matching dual-sheave (groove) pulleys on the crank and water pump as well.
Or you can convert the front accessory drive from the standard V-belt to a more modern serpentine belt system.
All three are effective, but some more so than others depending on where you want to end up.
We don't need much alternator power in our Broncos usually, but adding computers for controlling EFI and all that stuff really changes things. That's where a modern internally regulated and more powerful alternator comes in very handy. Gives forth with good clean and steady power even at idle. Which is where your stock style alternator starts to suffer a bit.
However, no matter what you do, you should be checking your wiring condition for any broken, stiff, burned or corroded wires and connections. Everywhere of course, but especially with regard to the regulator and the alternator.
Easy to pull it out and check things for tightness and cleanliness, and even take the alternator down to the local parts store to have them test it for you. Not all shops can, but these days most of them have that capability.
I suppose you could measure the voltage output on the Orange "F" (for "field") wire on the regulator to see if it's got a pulsing voltage. If all the wires check out, replacing the regulator might just do the trick.
About half the time this happens it's the alternator, and the other half of the time it's the regulator. Not sure exactly how to test a regulator though. Probably a way...
Good luck. Bottom line is you will probably not regret paying the extra money up front for a 3G alternator.
Paul
