The E type I bought to restore had the battery missing and also a lot of the wiring around it. So I am trying to rewire and will probably have more questions for you.
For now, however, the question is simple: Is the battery installed so that the negative pole is nearer to the front of the car? I think so but appreciate confirmation.
Phillip, First off , Good luck and welcome aboard…
It depends what year…If its a 61 to 64 its a positive ground originally, if it 65 and beyond its negative ground.
Your 1 wire will be a shorty to the 12 volt post the other to the firewall as a ground…
What year.
gtjoey1314
Phillip - you can add your car to your profile and it will show when you post (as I have).
I recall yours is a 68 so it is negative ground and yes, the negative post will be forward. Whether the posts are inward or outward is another question. I think they may have been inward originally but I find it more convenient to have them outward - also easier to find a suitable battery at Wal*Mart.
Here are a couple of photos that may prove helpful…
Geo, great picture, notice the braided wire/ground is to the left same as mine…
His is a 4.2 negative ground.
Now you can move things around but that set up is factory…
Great shot to the positive post as well!
GTJOEY1314
As long as we’re talking factory, here’s a shot of the original cables from my 1967. (Don’t ask me why I keep this stuff, but I’m glad I do.) The replacements currently on the car are the correct helmet style, but with black rubber sheaths. I don’t believe anyone makes a yellow rubber sheath today.
And, dang, these are expensive!
The ones I bought from SNG a couple of weeks ago are identical, the negative cable has the yellow sheath. Both of them together totaled about $110.
This is a picture of a late S1 battery in a SII car. The second picture is the battery that came in later SII cars. Terminals are on the inside.
Yes, Like Geo though, I bought a battery that put them on the outside for convenience.
Was the red painted lead positive terminal in your photo factory? if not that is a pretty good idea, IMHO.
And on eBay at the moment (though the terminals may be reversed):
Now that’s pretty cool they are available again. I last checked all the major suppliers two summers ago and they weren’t available then. Also, the facsimiles were more expensive at the time.
Thank you for info on battery orientation plus other comments which are interesting
Now I have two new questions:
First, where is the correct physical location in my car (68 Series 1.5 2+2) for:
-3AS ignition warning light unit,
-starter solenoid relay
-alternator relay
-voltage stabil izer
-reverse lamp switch
-flasher unit
-radiator fan relay
These are the exact descriptive terms used on the XKs Unlimited wiring diagrams I am using.
Separately, I observe that the wire colors in these diagrams (for Series 1 and 2) do not always conform to the actual wires in my car and in locations where I believe the wiring is original. My question is have you also noted these occasional discrepancies?
Yes but the worst of all evil is your year car…
You have to find your complete vin number and call sng or others and get ALL the wiring schematics.
Your not a series 1, your kind of series 1 1/2 and depending on the month your almost series 2 
Your wiring could be a mix of all.
Good luck.
GTJOEY1314
Starter relay…don’t think there is one on my car, the solenoid is picked from the ignition switch.
Alternator relay…by the battery bolted to the wheel well guard.
Reverse lamp switch…on top of the gearbox
Rad fan relay…mounted on the upper part of the picture frame.
3AS unit…between the LH bulkhead and the battery under the LH game.
Voltage stabilizer…,mounted on the back of the drop down dash, behind the guages.
I think all that is correct, if not someone will straighten me out 
Phillip,
When I had my '68 FHC the only wiring diagram that matched my car was the one in the back of the little blue owners manual. I used the Bentley shop manual and none of the drawings in there matched my car.
Rick
Mine is a S2 but possibly more similar to yours than a S1…
The 3AW -
I went with the electronic unit from CoolCat but hid it behind the old can.
Starter relay -
Mine is under the dash on the far right. Sorry no pic.
Alternator relay -
It is the second one down behind the battery (would be 3rd one from the top if you had AC):
Voltage Stabilizer:
Must be securely grounded to work properly.
Reverse lamp switch:
I added lot of extra wire in the hope that I could drop the engine & gearbox w/o removing the interior… though my real hope is that I never have to test that theory.
Flasher:
Radiator fan relay:
Thanks for replies on locations. The pictures obviously took some effort and will be a great help.
Is the answer to my second question about varying wire colors is that my car is “in between” standard model.wiring diagrams?
One more question to the photographer of the alternator relay. What is the relay looking device which is just above The alternator relay?
That is the relay for the horns.
Another question, perhaps for the wider group. In my e type hybrid 68 version, I now believe the alternator relay actually bolted to the mud flap on the bonnet. Another owner mentioned this long ago .
But now I am unsure where my horn relay fits. The wires attached to it will not allow it to fit where Ahwahnee’s great picture shows. Instead it seems to have been connected to something near the brake fluid bottles My car is missing the heat Shield but is it possible that the horn relay was attached to this shield just below where the brake fluid bottles were attached?