Voltage regulator

[x_atlas0]

Hello, everybody.

Quick question: how can I tell if my alternator has an internal voltage regulator? My alternator light is on, and I think it is the regulator, but that part is not where it should be. I read in the Hayes manual that I can check to see if it is the regulator by jumping the harness connection pin in a certain way.

Thing is, if it is the regulator, I have no idea where the thing could be, or if it is internal to the alternator. It is an obviously refurbished alternator, and I have a recipt saying someone replaced the voltage regulator in '92, but I have no idea what it would look like.

Hints, please?

 

[Philip Slate]

I know I will be corrected if this information is not correct, but I believe the difference between internal/external voltage regulator is that an alternator with internal regulator has only two leads, a hot lead and a smaller lead that goes to the light on the dash, whereas the external type has multiple wires and/or a spade connector for the B+, B-, field and other things I've long ago forgotten 'cause it's been a long time since I've played with an external regulator type unit.

 

[TILLA]

The coupes came with alternators with an external regulator which is on the left firewall adjacent to the high beam and horn relays. Since your car has a newer engine hopefully the swap included the newer alternator which would be of higher amperage. Another thing, the internal voltage regulator is a single unit combined with the brushes:

Mark

 

[x_atlas0]

It still connects to the rest of the car through the 3 prong connector. The main output ties to the starter and to the battery, it looks like a 10 gauge wire, it is a bit less than an 8 gauge.

I suppose that means it has an external voltage regulator. Are there any identifiers that I can use to tell if I have found the regulator?

 

[TILLA]

Here is a picture of the back of my alternator:

If it is the original type of alternator with an external regulator there will be a lead to the battery (B+) and a plug with three leads that go to the regulator (D-, DF, and D+) the D+ lead (blue wire) comes out of the regulator and goes to the gauge cluster wiring plug.

I take it that you don't have the regulator in the normal location by the battery next to the horn and high beam relays?

 

[gazzol]

The original (external regulator) coupe alternator as Philip stated has a battery wire and a multiplug which resembles the plug on the back of your headlamp units. If you wish to fit a later (internal regulator) alternator you can do so simply by cutting the blue wire on the multiplug and fitting a crimp terminal to it. This blue wire then goes onto the charge signal terminal of the alternator, note that there are two spade terminals on the back of the later type alternators one is for a noise suppressor the other for the warning lamp.

The voltage regulator is the oblong unit mounted to the relay bracket next to the battery. It has a similar style multiplug and the wire colours are (normaly) blue, black and brown.

 

[x_atlas0]

My alternator looks slightly different. The 3 prong plug goes into the unit more, and has a holder bar.

As I stated in my first post, the voltage regulator is not in the stock spot, and I highly doubt they replaced the regulator with another of the original style. That and I haven't seen anything that looks like the original voltage regulator. There is no socket by the horn and high beam relays, I'm guessing it was relocated or removed by a PO.

 

[TILLA]

I'm thinking that the regulator is internal, is there a label on you alternator? the remanufactured Bosch units have a small label that would say AL41X for example (which is one for a 528i and would be a likely candidate for a replacement, the stock alternator for a coupe would be an AL45X). That would confirm whether it has an internal or external.

Mark