I put on 20 miles yesterday. Light was on the whole time, car ran GREAT the while time. Stopped many times, restarted just fine. I think it's FIXED! Now to jump one final wire and get that light to go off.

Our Spitfire had a 5 wire alternator.  They are hard to find these days and it is common practice to convert to the 3 wire setup.  Thankfully... it's an easy conversion.

I'm sorry I missed it, how do you get rid of those things??

Hi Mark, been there only with a 5 wire system. Luckily I have a friend who sorted it for me, good luck

Many alternators will fit the mounts designed for Lucas alternators.  

At one time (as in Mark's case) it wasn't converting away from Lucas, it was that you were converting from a generator to an alternator.  When making that change, selecting a common alternator that is available locally makes sense.  Over the years several different alternators have been preferred due to their reliability and availability.  The Saturn conversion just happens to be one that has been popular in recent years.
 

hehehe , Being a somewhat social person, i'm fine with the social icons on the right, they prove to be a bit bigger on the bottom

Why fit some none STD. Alternator when you can buy a new Lucas that fits on STD mounts?

Sorry, you are right about the social icons, just temporary, I do see that the host has the option of making it horizontal at the bottom, may prove to be a little less in the way.

I have done that for several weeks now.  However, the bar only goes away temporarily.  As soon as I scroll up or down to look at another post, the bar pops right back up again.  I want to permanently get rid of that bar or move it to the other side where it doesn't block text.

Mark, if you haven't yet looked at the website I provided the link to earlier, take a look at it and review the first section dealing with the Saturn alternator.  It doesn't sound like it is too different from other alternator swaps.

I am curious about you having to grind away anything to mount the alternator.  I am used to the front alternator ear being "fixed" and the rear one having a steel bushing.  The steel bushing can be moved axially to get the length you need between mounting points.  I am only familiar with people having to modify the front ears or mounting points on the engine if the belt does not run true.  However, as I mentioned, I am not familiar with the Saturn alternator so maybe it is different.

DK. Thanks for the indepth description of the system. The car is about 15 mins away in town. I keep running out there and working on it, and think it is driveable home as it sits now. That will give me much more work time with it here.

When I mentioned the 3-5 volt jump it was mainly because the battery had run down to about 11, so the 13-15 max is where it is when running.

I'll look at what I've done again soon and repost. I like the idea of the knowledge base growing with systems like this.

Hi 63, To turn off the social icons hover over them and slide down to the little light gray right arrow and hit enter. On my charge lamp, with the generator a dull glow was common at low rpm's, now with the alt when starting warm or without fast ldle I get a full bright lamp that goes out like a switch with one blip of the throttle, no more that 1000 rpm or so. Charges great, starts great, light are full bright at idle. I just thought this was normal, no one in my area to compare to, darn few mini's in SE MI.

"...and in my case it take a little bump in RPM's off idle for the light to go out. I hate to think you have it right and just need to tap the gas..."

This is quite normal when using a generator..  However, one of the main reasons for going to an alternator is that they provide output from very low revs..  So, no, its not normal for the "ignition' light to glow at low revs if you're using an alternator... But I wouldn't worry about it as long as it does go out..

"..P.S. Is there a way to permanently turn off the social media icon bar that appears on the right margin of the webpages here? That thing is driving me nuts..."

YES .....PLEASE...

My conversion was from +ground Gen. to Alt. on a 62 with an original harness, I found good information on this site, but these photos would have been helpful. By the way, all item are removed from inside regulator, and make sure links are below the mounting surface.

Yes he is mur.

Are you replacing a generator with an alternator? What did you do with the external regulator and related wiring?

I converted to the Lucas 3 Wire, and in my case it take a little bump in RPM's off idle for the light to go out. I hate to think you have it right and just need to tap the gas.

No, the charge warning light does not get its ground connection through the socket base.  It's exactly the opposite.  You must have a two wire lamp socket for the charge warning system and the base must NOT provide a ground for the light bulb.

In the charge warning lamp circuit, current flows from a white wire on the ignition switch, to/through the charge warning lamp, and on to the small terminal (stator windings) in the alternator.  The other end of the stator windings in the alternator provides the ground connection that allows the warning light to come on when the key is in the run position.  As mentioned by others above, when the alternator starts making electricity, the internal circuitry raises the small terminal on the alternator "up" to the system voltage (effectively taking away the ground).  Therefore, when the alternator is charging the battery, there is no voltage across the warning lamp and it turns off.

I believe you said that you converted an old control box to be the junction box for the wiring.  To paraphrase what that should look like....  Under the control box, ALL the large terminals are joined to each other.  Likewise, all the small terminals are joined to each other.  Then all the old wires go back on the control box where they were EXCEPT for the BLACK control box ground wire.  Do NOT connect the old black ground wire.  Tape it up out of the way so it doesn't confuse you in the future.

If you must run a separate wire for the charge warning lamp, run it as I describe in my second paragraph above.  Also, visit the Britishwiring.com website and buy the correct color wire.  Troubleshooting in the future will be MUCH easier with the correct color codes.  In this case, you want the small brown/yellow wire to run from the alternator's small terminal to the charge warning lamp.

3-5 volts increase with the engine running is too much.  A fully charged, healthy battery will be measured about 12.5V when it has been resting for a while.  With the alternator charging you want to see the voltage across the battery somewhere between 13.5 to 14.5 volts.  15 is sort of OK but pushing the upper limits, 13V is questionably low.  A 5V increase would take you upwards of 17V and that will boil the battery dry.

P.S. Is there a way to permanently turn off the social media icon bar that appears on the right margin of the webpages here?  That thing is driving me nuts.

I'm getting more confused. As I mentioned, I have a wire going from the indicator wire on the alternator directly to the gen bulb bypassing the harness. (That was one of my issues). I had the other wire from the bulb going from the positive end on the coil. I read the wiring diagram and started bypassing the harness to establish what was working and what wasn't. When the light came on with the ignition (keep in mind it WASN'T in the dash) I started replacing the wires with harness wires until it didn't work, essentially a process of elimination.

Here are my questions:

1) Does the holder of the gen bulb need to be grounded in the binnacle to work? It's in, but won't go out when running.

2) are there additional wires that need to be bridged so the wiring can be complete and shut the bulb off when running?

3) as mentioned I get 3-5 volt jump when reading at the battery running vs not running. This is with the light continuously on. I just don't want to drive with a red light on!

Can't tell you how much it sucks having a Cooper S and a Lotus BOTH with wiring issues in Michigan during record high temperatures. I just wanna drive!!!!

Just to add that the other side of the ign light is connected to the ign switch when you switch on the Ign. This provides the feed to light the light and excite the alternator

If you have the alternator wired correctly, the red light comes on when you turn on the ignition.  Power flows (through the bulb) to create the static magnetic field in the alternator.  When the alternator spins up (i.e. engine starts) the magnetic field is energised by the alternator.  The charge indicator bulb now sees 12 (ish) volts at both its terminals, so no current flows and light goes out.  So, yes the light is an important part of the alternator system...

No light = no output/charge. EDIT: No light when there should be light..ie with ignition on but motor not running = no charge. Light on when it shouldn't be (motor running) also = no charge......

My (generic) alternator has three spade terminals, marked + + and IND.  The first + is connected using heavy wire (it carries the full output) to the battery terminal on the solenoid while the lighter wire connects the IND terminal and the light...

Seeing that you have just installed the alternator you will need to check what you have done with the wiring noting that the old regulator is no longer required as the alternator is internally regulated....

Cheers, Ian

I have never worked with the Saturn alternator.  There are a couple of good web pages that discuss it.  The website linked below should be of some help.
//www.britishcarforum.com/bobmuenchausen/17901.html

On the Lucas and Delco 10SI, 12SI three wire alternators the warning lamp must work for the alternator to start charging the battery.  

In general, if you see a 1.5V to 2V increase across the battery after you start the engine then the alternator is making electricity and the battery is charging.