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  • Dean Mericas’ Triumph TR4 Project
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Category Driving Impressions

Converting your classic car to self-regulating Alternator

February 14, 2017 Posted in  Driving Impressions | Comments: 0

Author’s note:  Although this article deals specifically with an older Saab alternator conversion, the identical concept applies to any vehicle of similar vintage.

Charging systems for automobiles have come a long way since the ’60’s.  Older systems relied on generators, or first-generation alternators to produce current, then a connection was required through a separate voltage regulator to complete the system.  All those connections and contact points (regulators) conspired to create constant issues with the system.

Then GM introduced the self-regulating alternator, requiring no separate external regulator, in the form of the now-ubiquitous Delco 10SI and later 12SI alternators.

So when recently the charging system in my venerable 1967 Saab Model 96 decided to take a powder, I was faced with the decision of spending a likely $150+ or so to rebuild my stock alternator (with a distinct likelihood of finding issues with the regulator as well), or just converting over to an inexpensive Delco 10SI alternator, eliminating the external regulator altogether.  Given that I had a couple of serviceable Delco-style alternators laying around the shop, and my waning interest in maintaining strict originality with my car, I opted for the “function before form” choice of the Delco “upgrade”.

As a bit of a primer, there are two styles of Delco self-regulating alternators available:  The so-called 1-wire (just hook up the alternator direct to the battery and go), and the 3-wire configuration.  The 1-wire can be tempting, but I have always opted for the 3-wire setup, as it allows provision for an alternator charge warning light circuit without further alteration.

The 3-wire unit consists of a central single terminal post which is connected directly (or indirectly) to the battery.  The remaining 2 wires are in the form of a 2-pin connector, which needs to be sourced for use with these alternators. Most any local parts store will carry these generic connectors.  I bought mine at an O-Reilly’s for about $3:

If you need to purchase an alternator new, you will find them everywhere for about $75 or less, usually with free shipping.  Of course, if buying from your local parts emporium, the genius behind the counter will want to know which car year and model, so you will have to exert a lot of pressure to get them to just open a few boxes until you get what you need.

The good news is all Delco 10si and 12si style alternators seem to have exactly the same mounting dimensions, so fitment shouldn’t be an issue.  When purchasing, pay attention to the alternator “clocking”.. i.e., what position on the outer case will the 2-pin connector plug in.  Although for the Saab, any one of the 4 clocking positions (12:00, 3:00, 6:00 or 9:00) will be workable, the best choice of a 9:00 clocking will position that plug right on the top of the alternator for easiest access:

The first step in working with any alternator installation is, of course, disconnecting the negative terminal of the battery for safety sake.

For the Saab-specific installation, there is a 3-wire plug-in connector at the OEM alternator which goes right to the 3-pin connector on the fender-wall-mounted regulator.  I just unplugged that cable at both ends and tossed it in the spare parts bin (you know, those parts you will NEVER use again!)

Next, I removed the larger gauge (estimated 10 ga.) wire from the alternator which connects right to the larger post on the starter.  There is another larger gauge grey wire attached to a second terminal on the alternator.  This is the main feed to the fuse block unswitched power buss.  The Saab manual’s wiring diagram shows this cable being connected directly to the large terminal on the starter (along with the previously mentioned wire to the alternator), so I followed that guidance, and connected both of those wires to the starter terminal.

A final connection on the Saab alternator was a black ground wire, attached to one of the case through-bolts.  The Delco alternators typically don’t have a provision for a ground wire, under the assumption that the alternator will be properly grounded through its mountings.  But since the lower block mount is isolated via rubber (see below), a ground-specific wire to the alternator seems like a good idea.

My own Saab  never had an operating alternator charge warning light (that’s why I had to discover my alternator’s failure when the car wouldn’t start one day!).  I found a small gauge (estimate 16 ga.) wire that some previous owner had just cut and left dangling from the wire bundle under the regulator.  Since that color corresponded to the factory wiring diagram for the charge light, I surmised that wire led directly to the dash light.  More about this later.

After removing the old alternator from the car, I could now turn my attention to fitment of the new(ish) Delco replacement.

The first issue was discovering that the beautifully crafted aluminum alternator mount is attached to the engine block through a pair of vibration damping (presumably) rubber fittings:

The problem is, there is a metal sleeve in the center of each of those rubber grommets.  Overtime, the rubber has shrunken so that the attaching bolts bottom out on those metal sleeves before the bracket itself gets firmly connected to the block, leaving a very wobbly situation.  I resolve that by using an angle grinder to whack off about 3/16″ of the length of each sleeve before reinstalling:

However, before reinstalling the alternator mount back to the block, there is another issue that must be resolved:  It turns out that the lower, wider mount on the Delco alternator is drilled to accommodate a 3/8″ diameter mount bolt, while the original Saab alternator (and associated holes in the mount bracket) is set up for a 5/16 bolt.  Something had to give so that the lower mount would be tight and wiggle-free.  I opted to just drill out the 2 mount holes in the aluminum original mount bracket to 3/8″, thus accommodating a 3/8″ bolt for a snug fit.

Additionally, I found that the new Delco lower mount tab was about 1/4″ narrower than the Saab, so I had to add spacer washers on each side when installing the alternator to the engine:

Now with the new alternator firmly installed in its new home, I was pleased to see that the pulley lined up perfectly without any modification to either the upper or lower mount:

It is time to attend to the wiring.

A generic wiring diagram for the Delco 10si is shown below:

Note that the rectangle junction depicted just underneath the DC-10 title represents the large terminal on the starter motor.

You can see the connections are pretty simple.  For the Saab-specific installation, make the following connections:

  1. Connect the grey wire from the alternator power post to the starter post
  2. Additionally, crimp a ring terminal onto the RED wire of the new 2-pin connector you bought, and attach that terminal right along with the grey wire described above, to the alternator power post.  This red wire connection is where the alternator gets its “voltage sense”.. i.e., it measures the battery voltage from here and uses that reading to engage or disengage the internal charging regulator.  For installations with the alternator further from the battery, it is advised to run this wire (the red wire) directly to the battery, so that true sensing of the battery voltage itself is measured.  For this installation, it will work just fine by connecting it to the main alternator power post.
  3. The white wire from the 2-pin connector is what powers the alternator charge light.  When the alternator is at rest, this wire becomes ground, and completes the power circuit from the light to illuminate it.  Once the alternator begins charging, this wire becomes a positive voltage, thereby negating a circuit for the charge light.
  4. Temporarily unscrew one of the through-case screws on the alternator, and reinstall it while capturing the black ground wire terminal as from the original installation.

That is all there is to it!  These instructions are equally applicable to vehicles original equipped with a generator (you can even buy a 6 volt alternator if appropriate), and in any case, following the simple connections as described, while abandoning/removing wiring from the regulator, will give the desired results.  For those with generator installations, there are plenty of generator-to-alternator adjustable mounting brackets to be had with a simple Google search.

To test your new alternator installation, with the engine running, just attach a voltmeter to the negative and positive terminals on the battery.  A good alternator should output 13+ volts at idle rpm, and should jump to 14 – 14.5 volts with the engine revved up.

 

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The Queen’s Revenge

December 8, 2016 Posted in  Blog, Driving Impressions | Comments: 1

For several years now a British Ariel Square Four motorcycle has remained stubbornly on my bucket list of interesting bikes to own.  Nope, had never seen nor ridden one in real life, but I have just always loved the classic British lines and the unique ‘square’ cylinder configuration.

Many Americans are unfamiliar with the Ariel motorcycle brand, but the marque is well known in England, where the Ariel owner’s club is very much alive, active, and well. In its heyday in the ’50’s, the Ariel was considered one of the premier bike brands in England.  In terms of rarity, there were fewer Ariel Square Four bikes built than the well-known Vincent Black Shadows which now routinely command 6 figure prices.

In fact, Ariel, which produced its first motorcycle in 1902, could very well be considered the Harley-Davidson or Indian of British bikes. 

Although Ariel produced quite...

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Those Hardy Swedes

May 16, 2016 Posted in  Driving Impressions | Comments: 0

It has been a year now since I was introduced to “Sven” our 1967 Saab model 96.

“Keep Austin Weird” is the motto in these parts, and I feel I am making my contribution by driving this quirky vehicle, a car that has quickly become my hands-down personal driving favorite.

“Weird” is perhaps too kind a descriptive term for “Sven”.

saab-email (2 of 2)

Everything about this car stands out in stark ...

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The Open Road Beckons

May 16, 2016 Posted in  Driving Impressions | Comments: 1

When spring comes to Texas, a motorcyclist just naturally begins thinking of hitting the open road.  Texas weather conditions  can range from icy winters to brutal summers.. Only a narrow window of riding opportunities are left in spring and fall.

To take advantage of that lovely spring weather, I texted my biking buddy, Nathan Gibson, in early April, with the suggestion that we take a long trip east.  Nathan, in true trooper fashion, responded promptly and positively, and suggested that we ride to his home town: Humboldt, Tennessee (a couple of hours northeast of Memphis).  That sounded good to me, so we set a date and made a commitment to each other.

Su...

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Barber Vintage Motorcycle Museum

May 3, 2016 Posted in  Driving Impressions | Comments: 0

Anyone who appreciates the fine workmanship of mechanical excellence would enjoy the Barber Vintage Motorcycle Museum.. arguably one of the finest collections of vintage motorcycles in the world.

20160426_133334

This museum is located in Leeds, Alabama, just outside Birmingham, and nestled beautifully amongst a pine tree forest.  The museum owns some 1400 motorcycles (according to its own website), with around 700 bikes on display at any given time,  The 5-floor glass and steel building is reminiscent of the BMW Roundel museum in Munich.

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The 8 Best Cars I’ve owned

April 3, 2016 Posted in  Driving Impressions | Comments: 0

I have always been a car guy, dating back to when, at age 15,  my brothers and I bought a neglected 1936 Ford from my uncle for $50 (we never could get it to start on its own power, but had a lot of fun pulling it behind a truck to start, then bombing around our ranch in the old beast).

At last count, some 80 cars and motorcycles have resided in my garages over the years.  Of these vehicles, just a few stand out as my all time favorites:

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10 Tools no shop should be without

November 29, 2015 Posted in  Driving Impressions | Comments: 1

If you follow this blog, most likely you personally perform some maintenance and/or repairs on your prized vehicle.

Sure, most of us car guys aren’t professional mechanics, but we do enjoy occasionally turning a wrench in the garage.  There is a collection of tools I have found over the years to be essential for the complete mechanic:

Leatherman...

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A Tale of TWO Buicks

November 29, 2015 Posted in  Driving Impressions | Comments: 0

When my wife and I began our search for a 1940 Buick Series 90 Limited, little did we know that we would wind up with TWO Buicks.  Well, to clarify, there is only one Buick “vehicle” in our garage, but it is a composite of two different cars:  the original Buick body and interior, combined with the running gear (engine/transmission/rear axle) from a 1972 Buick Electra. The Buick Electra drivetrain was pretty awesome for its time:  455 cubic inch V8, driving through GM’s TH400 automatic transmission.  But more about that later.

buick (2 of 3)

We had been looking...

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Attempting the “Ton” on a 1927 Scott Motorcycle

November 29, 2015 Posted in  Driving Impressions | Comments: 0

Back in the 60’s and 70’s, the Ace Cafe in London was THE place for motorcycling enthusiasts to hang out.  In fact, legend has it that the Ace constituted the origin of the term “cafe racer” (not necessarily racers at all, but stripped down bikes to “race” from cafe to cafe).  This was the heyday of the great British bikes.. Triumph, Norton, BSA, etc.  Of course, the big goal of period riders was to “do the ton” (100 mph), and manufacturers were competing to produce bikes that could do just that.

Fast forward 50 years to the home of Lago Vista...

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Must-do events in November (2015)

October 15, 2015 Posted in  Driving Impressions | Comments: 0

You don’t want to miss attending the always popular Rolling Sculpture Car Show (my local favorite), held this year on November 1, at the Hill Country Galleria. A great location, and a great collection of cars, at just the right time of the year.  Click on the poster below to visit the show website:
2015 rscs poster final 800px wide

 

 



 

2015 SHOW & SHINE CAR SHOW AT CIRCUIT OF THE AMERICAS

Be a part of the SVRA “2015 U.S. Vintage National Championship” Race Weekend held at the 1,500–acre Circuit of the Americas (COTA) complex in Austin, Texas! The dramatic and natural elevation changes of this 3.4-mile, 20-turn circuit will provide hundreds of vintage race cars a challenging experience you will not want to miss!

The Classic Car Show at COTA on 10:00am Saturday, November 7th is open to all Classic, Vintage, Exotic and Collectible Cars and Motorcycles of interest. Each ***$75.00 Car Show registration includes:

– 2 Weekend Passes (2-day) to the Vintage Races  (Saturday/Sunday) and
– 2 Two ( 2-day) Motostalgia Auction Guest passes (Friday/Saturday, everyone registered for the Auction will receive dinner at the Sat. night auction)
– The “Last Lap” tour of Circuit of the Americas in your show car (subject to track conditions)
– Guided Tour of the Paddock
– Saturday Evening Concert – “The Marshall Tucker Band”
– Saturday Evening Fireworks
– Optional Driver Dinner (additional charge)
– Complimentary Event Program
– Complimentary Special Event Race Poster

***$75.00 online in advance.  $ 85.00 day of show.

CLICK HERE to visit website and register for the show

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