Series 1 E-type Alternator Upgrade

Do-It-Yourself Alternator Upgrade for Series I E-Type


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Do-It-Yourself Alternator Upgrade
for Series I E-Type 

By Ray Livingston 

Tech Archive Index


posted 06-18-2003

Here is the information on the alternator conversion I've developed
for my own Series I E-Type. If you have any questions, or run into any
problems, feel free to contact me by E-mail:

Ray Livingston

I'll be happy to provide whatever assistance I can. When you're all
done, I'd love to hear how it went, and how you like your new alternator.


I developed this upgrade for my own use, and I am offering it to others
as a courtesy only, and on a strictly AS-IS basis. USE THIS INFORMATION
STRICTLY AT YOUR OWN RISK!! I will accept absolutely no responsibility
or liability for anything that happens as a result of your use of the information
presented here.


The Hitachi alternator for a 1986 Nissan pickup is a perfect replacement
for the Series I E-Type generator. It is small (roughly the same size as
the Lucas alternator on 4.2L E-Types), internally regulated, readily available,
and cheap. For about $200, and a few hours of easy labor, any Series I
E-Type can be upgraded, and banish charging problems forever. My own 64

was plagued with charging problems before I made this modification.
That was 2-1/2 years ago, and I havent had a single problem since in almost
8000 miles of driving. This alternator can also be easily fitted to a Series
II in place of the Lucas. If you want to try this, contact me for details.
Heres what mine looks like:

BTW - You can also see my $200 aluminum radiator in the background.

I originally considered using a Delco alternator, as this is a common
upgrade. However, the Delcos are considerably larger, and just dont look
right in the E-Type engine bay. Also, I have the double-V belt drive. Using
the Delco alternator would have required machining a pulley, as the shaft
size is not the same as the generator. Changing to a single-V belt would

changing both the crankshaft and water pump pulleys, which would be
very expensive. In addition, most Delco alternators are capable of putting
out enough current to fry the wiring in an E-Type.

This upgrade, on the other hand, looks reasonably correct, since the
Hitachi alternator is so similar to the Lucas. You can use the generator
pulley, and retain the double-V belt. All parts necessary to mount the
Hitachi are readily available, so the only fabrication thats required
can be done with a hacksaw. There are no irreversible modifications to
the car whatsoever, so

the generator can be re-installed at any time. Warning: you must
convert your car to negative ground before doing this conversion!!
you want to learn how to do this conversion, click


  • Alternator: Lester/Rebuilders number 14231 $50-70, available from any
    auto parts store. Take your generator pulley with you, and make sure it
    fits the shaft on the alternator. I think the #14255 alternator is mechanically
    identical, but 50A output, which would be required if you have AC.
  • Universal alternator adjusting bracket - $8 from most auto parts stores.
    This is the slotted bracket used for adjusting belt tension. The universal
    ones are made for Detroit V-8s, so they are really long, but you can cut
    off the excess. (See the photo below)
  • 3.8 alternator mounting bracket - ~$130, available only from XKs Unlimited.
    This is a bracket made for mounting the Lucas alternator on the 3.8 block,
    which does not have the cast-in alternator mounting bosses of the 4.2 block.
    If youre handy with a welder, you could easily make your own bracket.
  • Series 1 4.2 Alternator belt - ~$20, available from XKs Unlimited. This
    is identical to the generator belt, except a few inches longer. If you
    have the double-V belt, this is just about the only belt you can use. The
    only alternative Im aware of is using
  • one or two 3/8 wide single-V belts, which are available from auto parts
    stores. This is what I used for the first few days, until the new double-V
    belt arrived.
  • A short 3/8 pipe nipple available from any plumbing, hardware or home
    supply store. Cut a section ¾ long. This is used to make a spacer
    for the lower mounting bolt to set the fore-aft position of the alternator,
    so the pulley lines up with the water pump pulley.
  • A ¼ ring terminal This will replace the 3/8 spade terminal on
    the large brown output wire from the generator. Find one suitable for at
    least a #8 wire.
  • Two ¼ male spade terminals, and a short length of 12-14ga. wire.
  • A 5/16 x 5 hex bolt, two flat washers, one NyLock nut, for the alternator
    lower mounting bolt.
  • A 5/16 x 1 hex bolt, flat washer and split lock washer for the alternator
    upper mounting bolt


The first step is to disconnect your battery, then completely remove
the generator, along with its mounting bracket and belt. Remove the upper
generator adjusting arm, which is held in by one of the timing cover bolts.
Save the bolt and spacers.

Remove the voltage regulator, mounted under the heater. Make two modifications
here. First, open the regulator (this may require drilling out the pop-rivets
holding the plastic cover on. They can be replaced with small machine screws
and Nylock nuts.

First we must establish a permanent connection from the alternator output
terminal to the battery, through the heavy-gauge brown wire. Locate the
cutout relay, which is the one towards the back of the regulator, and wedge
a small piece of cardboard into the arm, so the relay is forced closed
all the time. This is shown in the following pictures. The cardboard is
the little blue thingy with the number 1 on it, on the right-most relay:

Heres a closeup of just the cutout relay, showing the cardboard more

Next, we need to create a connection from the old generator field wire
to the idiot light in the speedometer. This will be used to drive the idiot
light. Disconnect the green and yellow wires  from the regulator.
Using the two ¼ male spade connectors and 14ga. wire, make a short
jumper, to connect these two wires together as shown in the following picture:

Now replace the cover, and re-mount the regulator, tucking the green
and yellow wires behind the regulator, as shown here: 

Remove the pulley and fan from your old generator. Re-use the bracket
bolts to mount the new alternator bracket to the block.On the new alternator,
remove the nut securing the pulley to the shaft, and remove the pulley,
fan, and the spacer tube behind the fan. Cut the spacer down to 3/8 length
as shown in the following photo.

Re-install the spacer, then the fan and pulley, securing with a lock
washer and nut. Tighten the nut securely, as we are depending entirely
on friction to fasten the pulley and fan to the shaft, since the Hitachi
shaft does not have a keyway. This may seem odd, but it works just fine.
You can use Lock-tite if it will make you feel better, but it really isnt
necessary. In fact,

many Delco alternators mount the fan and pulley in exactly the same
way. Heres what it should look like when youre done:

Mount the alternator to the bracket using the 5/16x5 bolt, inserted
from the rear. The bolt goes through the rear alternator flange, a 3/8x
3/4 pipe spacer, the rear mounting bracket flange, the front alternator
flange then the front bracket flange. One the front end of the bolt, use
a flat washer, followed by the Nylock nut. Once bolted together, make sure
the pulley is lined-up

properly with the water pump and crankshaft pulleys. If it is not,
fabricate a new spacer from the 3/8 pipe to make it line up properly.
Heres what it should look like when youre done. You can see the 3/8x3/4
pipe spacer on the right:

Next, fit the belt (it will probably take some effort, as the belt is
just a bit too short), and determine where to cut the universal alternator
adjusting arm so it will fit. Then drill a 5/16 hole in the cut end, to
be used to fasten the arm to the front of the engine, using the same bolt
as was used for the generator adjusting arm. Heres what my arm looks like,
after cutting and drilling:

This arm started out at least twice this long. Mount the arm to the
front of the engine. I was able to re-use the same spacers that were used
on the generator adjusting arm. If that doesnt work for you, just stack
washers on the mounting bolt to space the arm out so it lines up with the
adjusting bolt flange on the alternator. Use the 5/16 x 1 bolt, flat
washer and lock washer to fasten the arm to the alternator, adjust for
proper belt tension, and tighten the bolt. Heres what it should look like:

All thats left now is the electrical connections. Remove the 3/8 spade
terminal from the generator output wire, and replace it with the ¼
ring terminal. Connect the ring terminal to the large threaded post on
the back of the alternator. This is the output connection, which is now
connected directly to the battery, so make sure its not touching anything
but the threaded post.

Connect the green field wire to the L terminal on the alternator, which
is the lower of the twoconnections on the left side. Heres a picture:

Re-connect your battery, and you should be in business! To make sure
everything is OK, put a DVM on the battery terminals. It should be reading
about 12.5V. Start the engine, and using the choke lever, raise the idle
speed to about 1200-1500 RPM. The battery voltage should increase to something
in the neighborhood of 13.5-14.5V. If it does, youre good to go. If it

not increase when the engine is started, check all your electrical
connections. If it rises much about 14.5V, check the wiring on the green
wire, the jumper behind the alternator, and make sure your idiot light
bulb is good. If you have any problems or questions, or anything here is
not clear, feel free to contactme. Good luck, and let me know how you make