OB
Here is a photo. There are two battery posts which are directly connected to the battery by a long thick cable that runs under the car along the transmission tunnel. It appears out of the tunnel and goes upward to the UK passenger side of the engine bay bulkhead. In the photo if you look along the heater return hose, just above the middle you can see a large black terminal boot. Under this is the first post. Then just above it and running along to the left you can see a thick red pipe-like thing, running just behind the silver heat insulation shield. This is the insulation for the mains cable that takes battery current across to the UK driver's side post; which is that steel nut you see just below the LH end of the red insulator.
This is where to take the power for your efans, running it through a 40 amp inline fuse. The battery post has a Whitworth thread and sized nut on it!
Remove the battery + and - clamps! then you can safely undo this nut which is VERY hard to get at but it can be done, engine in car. It is sited just to the right of and below the wiper well drain tube, which you can see in the pic. The run the wire round the corner of the engine bay and down the wing to the efans. I pulled a bit of silicone tube over the efan feed cable when I ran it round to the wing and a straight run, to give it some extra protection against rubbing and shorting.
Greg

 

Hi Greg

Cheers!

That's just what I wanted, now I know what I'm looking for and hopefully where to find it, as long as my Marelli Car is wired the same as a Lucas.

 

Yep it's the same, my posts are in the same position as in Gregs pics. I used the LH post under the rubber boot.

 

Hi OB!

Long time, no talk! I hope all is well!

Just a quick thought - those bulkhead positive and negative posts are often the cause of erratic charging and also fluctuating instrument readings. When you've got it apart, check for any rust on the bulkhead, then clean up the posts and wiring comprehensively before re-installing.

Good luck

Paul

 

Hi Warrjon

Cheers!

Haven't had time to check it out, its been Raining All Day.

 

Hi Greg

Cheers!

That looks like the ideal place to make a connection and ditto with the Tubing to protect the Wires, I think I've got a reel of that somewhere.

 

Hi Paul

Good to hear from you and I'll make sure I clean up the Terminals.

Also got an Oil Change to do but its all gone horribly wrong!

I ordered some 5/8 in Dowty Sump Plug washers but because they were BSP, they actually measured 21mm way too big!

So now ordered 16mm (ides of March and all that!)

 

Paul good to hear from you. BTW, both the posts on the bulkhead are positive! (I mention this just in case having found that one is positive someone erroneously concludes that the other is negative!)


Also OB, FYI, if you ever have to take the dash out (not advised!) you will find the other end of these two posts is in the cabin side of the bulkhead and provides the main feed for the dash, fuse boxes aircon etc etc.
Greg

 

Hi Greg

I'm glad you mentioned that!

Though I'd like to think I would have sussed that out, though on a bad day maybe not (Lol)

(1) Where is the Best Place to Earth to

(2) Does the Relay go on the Positive Wire or the Negative

(3) Does the In-Line Fuse go on the Positive Wire or the Negative

As soon as I've got One Fan Running, then I can get into the Thermostat thing with the other one.

 

Hi Greg,

It's good to be back! Tks for the clarification on the polarity. As you know, I know a bit more about late cars than pre-facelifts. On the late cars, there are positive AND negative bulkhead posts which often confuses owners!. I naively assumed pre-facelifts might be the same. (Lesson: never assume!)

Cheers

Paul

 

Hi Greg

I'm glad you mentioned that!

Though I'd like to think I would have sussed that out, though on a bad day maybe not (Lol)

(1) Where is the Best Place to Earth to The earth bolt at the ends of the radiator top panel is fine, it already has earths there, just add another

(2) Does the Relay go on the Positive Wire or the Negative The relay needs TWO circuits, the low current switching circuit and the high current fan power circuit. The relay is an electrical switch that uses low current circuit to actually switch the high power current circuit. PM me a photo of the termincal on the relay you will use and I will explain. You need a relay rated for 50 or 60 amps or more. Lorry relays are good forthis sort of power.
(3) Does the In-Line Fuse go on the Positive Wire or the Negative The inline fuse goes between the bulkhead power post and the relay. Again I will send you a full diagram once I have the relay pic

As soon as I've got One Fan Running, then I can get into the Thermostat thing with the other one. I will try to explain the G Francis system with the diagram.

 

Alex,

I make a better coffee than I draw.

This is rough, and I mean rough, but I reckon you can follow it.

If not, drink more.

Still unclear???, let me know, I will do it again, and stay sober whilst I do so.

Thermo fan wiring drawing (1).pdf

 

Hi Greg

I think I get what you mean now, so I am ordering some Pre-Wired Relay Sockets.

One of the things that was throwing me was why you needed Two electrical feeds, so does that mean I can use thinner Wire for the Switching Circuit?

 

Hi Grant

Cheers for the drawing, I think that I get it!

And have ordered some Relay Holders Pre-Wired and when they arrive will do a bit of a 'mock up' before connecting it up properly.

 

I've got to do an Oil Change as soon as the Weather calms down and so decided to buy some new Sump Washers.

Instead of the Normal Copper Type, I thought I would try these instead.

They are 16mm Dowty Washers and they are a very snug fit on the Sump Plug

(The Plug in the Photo is a Spare from my Parts Car)

But do you think these Dowty Washers would be any good for this purpose.



Dowty Washers, for use on the Sump Plug of my V12 XJS.

 

Yes, these seal very well, I used them on the oil dead weight testers to seal up to 10,000psi.

DO NOT over tighten them or you will damage them. Check specs for washer.

 

Hi Warrjon

Cheers!

They seem to be a perfect fit for the Sump Plug and much better than the loose Copper type that I have been using before.

And I will remember not to over tighten them.

 

Pre facelift do have negative/ground posts on firewall also. They are smaller and most likely capped with plastic acorns.

 

That is interesting Warren. Out of interest, could you let me know where are they, as I did not notice anything on my 1985, or I have forgotten them! The main earths were, as I remember, on the inside of the cabin to the bracing struts each side of the Delanaire unit, and dotted all over the engine bay as required.
Greg

 

After the debacle of my last Oil Change, where I got covered in more Oil than the Deck of 'The Exxon Valdes'

This time I was determined to try and get it right!

While I've always used Magnatec 10/40 Semi Synthetic, this time I decided to try a different Oil.

This is a very good quality 10/40 Semi Synthetic, that normally retails in the ball park of £73 for 20 Litres.

That was on Special Offer: 20 Litres for £36 including a Mann Oil Filter!

So I decided to go with that.



20 Litres of 10/40 Semi Synthetic £36 including a Filter!

This time when I put the Car on the 'Lifter' I only had her Two Feet off the Ground, which made everything easier to get to.



As I'd replaced this Filter before, I only did it hand tight, so taking it off to replace it was dead easy.

Before I started draining the Oil, I cut the side out of a Plastic Container to drain it into.



This time I never spilled a drop.
Well maybe just a couple!

Before I replaced the Oil Filter, I filled it up 3/4 Full with Oil which helps to get the Oil Pressure up much quicker (Hopefully!)



Before Replacing the Oil Filter, I filled it up 3/4 Full with Oil with a Smear of Grease around the Sealing Ring.

Instead of a Copper Sump Washer, this time I used a Dowty Sealing Washer, which some say are better that the Copper ones.



This time I used a Dowty Sealing Washer, instead of the Copper Type.

'Nothings Too Good For My Baby' So this time I flushed the Engine with a Gallon of 'el cheapo' 10/40 Semi Synthetic, that was laying around my Garage.



This time I Flushed the Engine with a Gallon of el cheapo Semi Synthetic, which I had laying around the Garage.

After which I put in 'The Good Stuff!'



Quality Semi Synthetic 10/40 about to go in.

Then I checked the Level on the Dipstick.



That looks near enough to me, so time to Start Her Up!

Now for that 'Heart Stopping Moment' waiting for the Oil Pressure to Build and trying to convince myself that I didn't forget to put the Sump Plug back!

And so I made a Video to show you how much difference filling up 'The Oil Filter' can make.

The Video is the First Start up after doing the Oil Change, which you can tell by the RPM.(1100) When She's Warm then She will idle at 500-700 RPM.

Near enough Instant Oil Pressure. Yesss!