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Wiring Harnesses

Wiring Harnesses

Rewiring - wiring harnesses

22 Nov 1996, from: Rob Reilly: Dave in WI asked about his '54 XK 120, can you
recommend a specific product/harness/partial harness? Moss Motors had a plastic
harness on closeout sale last month. Find the right wiring diagram in the
manual, make a Xerox of it, and get it zoomed up to 200%. I carry a copy in the
car all the time, along with a voltmeter.

28 Feb 1997, from Robert Oates: Thanks for providing additional reference
sources. I noticed that XKs Unlimited also provides electrical diagrams for the
XK series @ $19.95 each. I just placed an order with them today. I suppose
I'll use the diagrams as additional reading material since I completed
installing the new harnesses in the 150 FHC during the past week end. Now for
the trouble-shooting phase. For me, routing the harnesses per original was the
hardest part. Hooking up will be easy. Speaking of guidance material for
rewiring work, I buy my harnesses from Rhode Island Harness. As many of you
know, they supply their own diagram with each harness. These diagrams are well
layed out and clear for me to follow. And they have been accurate. Cheers, Bob

1 Mar 1997, Nick Saltarelli, XK120 OTS 54: I am looking for advice on buying a
wiring harness for my 120. Guy Broad lists a complete harness at pounds 170.80
(about US$280) while Rhode Island Wiring lists separate sub harnesses that add
up to more than US$800. I get the feeling this may be an apples and oranges
comparison. So, anyone have an idea about how these items might compare?

Nick, Had a similar problem with my XK150. I determined that Rhode Island
really sells all the separate harnesses lighting, underdash etc. while most of
the overseas harnesses are complete. The bad news is the harness I bought from
England was wrong. I specified cloth, so the vinyl was wrapped with cloth. You
would not believe how hard it is to get an oversize bundle through a grommet!
It also did not contained diagram or even a packing list. About 30% of the color
code was wrong and the few end connectors that were included were incorrect. I
summary I believe the harness was designed to be a cosmetic upgrade for someone
who had all the connectors, a complete working harness and plenty of time. I had
none of the above and it was a nightmare. Rhode Island will custom make the
harness and you have someone to call if you need help. Good Luck, L J Haithcock

1 Mar 1997, from: James Warren: I have a listing from "The Jaguar Warehouse"
5389 Ashleiggh Fairfax VA 22030 (703) 968-3983 which shows _New wiring looms,
made in UK, lacquered braided just like originals, $450/ea (specify LHD, RHD,
early or late cars)". Sounded good to me, but I haven't inspected the product.
Anyone with experience with these? The person I spoke to said he travels to the
UK personally to buy stuff. They also have used and reconditioned
miscellaneous parts. Grilles, carbs, complete fuel and brake line sets,
reporcelainized headers, etc.

2 Mar 1997, Nick, the leading wiring harness source in UK was AUTO SPARKS in
Hull for a long time. . I bought the cotton braided XK 120 harnesses for my OTS
and FHC. Both
were exellent. Auto Sparks relocated some years ago to Nottingham. The address
as the Classic & Sportscar Directory 1996 lists it is:
Auto Sparks, 80-88 Derby Rd., Sandiacre, Nottingham, Nottinghamshire, NG10
5HU, England
Tel: 44 115 949 7211 Fax 115 949 1955
When you order a XK wiring harness, make sure, that you order exactly what your
car was up to. There are many different harnesses and if you get a wrong one it
is very often due to wrong order. Reasons are: LHD or RHD, for instance, the
stop light switch cable is not long enough if ordered wrong. Same with Indicator
cables. That rings a bell: There were even XKs without indicators. In that case
there would be no wires included in the braided cover. Such a wiring harness you
would never get properly installed. Think about the stop light interrupter
relay. That alone takes 8 wires. If in doubt, have a look in the original
service manual for Mk7 and XK120 before you order. There are no less than 15
diagrams listed for Mk7 and 120s. 
My experience with Auto Sparks was, that they supplied according to the original
color codes and to my full satisfaction. Arno Wahl 

I installed a wiring harness from Rhode Island Wiring for a fellow a couple of
years ago. It was very high quality. The car had overdrive and that part of the
wiring had to be redone. The vendor had no problems in redoing that part of the
harness. Each sub-harness was labled and reduced the guesswork time. This
harness was for a XK140. Cleo Bay, XK120, XK140 

Larry's stuff from Va. is excellent... and it's correct. John Shuck.. Beijing

2 Mar 1997 Here's one more endorsement of Rhode Island Wiring. I used one of
Engine Compartment harnesses in my (120) OTS, rewired my FHC completely with
their harnesses, and am about to install their Engine and Alternator harness in
an E-Type. 
I have been very satisfied with the accuracy and convenience of their
installation diagrams and with the quality and authenticity of their material. I
strongly suspect that they are the prime wiring supplier for several of the
large Jaguar Parts Catalog companies. I don't know if they have the lowest
prices, but their products and service are excellent. How come my cars look the
same and I look so much older? Dick Cavicke 120 OTS, FHC E-type, in work.

3 Mar 1997, from: Robert.Oates: Here's my rewiring thoughts. In 1980 I did a
body-off restoration of my 150 OTS. It was perchance that I selected Rhode
Island Wiring to furnish the harnesses for this vehicle. I found them through
Hemmings or from Bill Tracy or perhaps from fellow enthusiasts at the Hershey or
Carlisle, Pa. shows. At any rate, I bought all the harnesses from Rhode Island
and began. I received tips from Bill Bassett directly and through his late 70s
publications (which I believe may still be available). I also was in contact
with the Rhode Island folks who provided me with assistance. Upon reflecting
about this experience, I will share with you some similar ideas as others have
expressed and as I also experienced. I will confine my comments to the 150

I have found that rewiring is easiest if done early in a total restoration.
That is, I rewire while the car is a shell upon a finished chassis. I don't
have major mechanical items installed at this stage of the process. I rewire
early so I can have the maximum amount of working space. So, with this mind,
here goes. 

1. Carefully identify the requirements of your vehicle. Order
Rhode Island Wiring Service's catalog for reference and general pricing even if
you don't buy from them. (1 800 241 1955). Note the designation between
"early" and "late" 150s. Identify your car. Note that harnesses were different
between those equipped with overdrives, automatic transmissions, and the
150/150S. Without insulting anyone's intelligence, also note that different
body styles initially required different harnesses. 

2. Get a good set of wiring diagrams. As in everything else, all
wiring diagrams are not equal. Having gone through one rewiring and now
finishing my second on the 150 FHC and still yet looking at my 120 OTS, I am
questing for the ultimate diagram. With my average mechanical skills and
knowledge of these vehicles, the Rhode Island diagrams served me well. As
others have noted, there are surely other good diagrams available. 

I am well aware of the one-page, comprehensive wiring diagrams originally
supplied in the owner's manuals. To those who have solely used this as a guide
to successfully complete a rewiring effort on an XK-series vehicle, I commend
you. In my opinion, these documents are
for electrical engineers or those who enjoy reading any literature about the
marque and perhaps will never undertake total rewiring of their vehicle. 

For me the best diagram is laid out on one sheet for each harness. Merging all
the harnesses on one sheet is a nightmare to sort. The major harnesses, i.e.,
cowl and engine have over 300 ends or termini. Find these on one sheet! It is
not worth it, folks. One harness layed out on one sheet of paper depicting that
harness is the only way to go. 

3. Stringing the harnesses. I start with the most difficult
harness, at the cowl (dash or firewall). You cannot install a new,
after-market, cowl harness through the firewall hole located under the voltage
regulator and at the rear of the fuse box. Definitely don't put the grommet in
place and try to pull the harness through. As they say, "Been there and done
that!" Here's the secret: enlarge the hole about 1/16" all around with a file
or suitable grinding tool before you get the harness in place. Check your
enlargement by constantly refitting a new grommet. As long as the grommet will
hold, that is, you have not cut too much metal, you are ok. If you do remove
too much metal, the harness running through the grommet will hold it in place. 

Slide the cowl grommet on the harness end that goes to the instrument panel.
Place this end through the enlarged hole. To those who have "snaked" house
wiring in place, I always tape the ends carefully. Get a helper with one
person inside the car and the other at the engine where with some twisting and
shouting the harness can be fed through. As the
person inside guides it through a passage way with small access openings, the
other person pushes it through. After the harness is in position, you can fit
the grommet in the metal.

Next I tackle the engine and headlight harness. I consider this the second most
complex harness on the 150. This harness leads from the fuse box along side the
right hand inner fender panel and is held by 2 or 3 metal supports. It goes
through the inner fender panel near the top center of the right front tire.
This opening, lined with a grommet, also must be enlarged. Use the same
approach as for the cowl harness. 

The next harness that takes the most time to install is the fuel tank/pump
harness. If the old harness is still within the frame, tape it to the new one
and pull it through. If the old harness is not there, I would use mechanics
wire to pull and guide the new harness in the frame. The rest of it is easy.

I consider the other harness and their routing easy because they are small in
size. Once you have the above 3 main harnesses installed, the remaining work is
simple and straight forward.

4. Attaching the harness termini. This is the fun part. Now you
know if pressing the horn button makes the horn blow. Even though I recheck
myself, I still have small mistakes during this hook-up phase. I try all the
electrical components and have a multi-tester handy to check out continuity. I
have previously made certain that the components are operational.

I could go on and on but... Happy rewiring all, Bob Oates.

3 Mar 1997, from: Robert Oates: Regarding a firm called "The Jaguar Warehouse"
in Virginia, I have purchased various parts from Larry Springer, the owner,
since 1974. In fact, I just bought his complete harness, made in the UK, for my
120 OTS. As many may note, I have purchased previous harnesses solely from
Rhode Island Wiring Service for my 150 OTS and FHC. I bought the 120 package
from Larry because I saw that it was a quality product and the price was right.
I have enough experience on the 150s to know that the 120 will be easy. The
shortcoming on his offering for the 120 was that the wiring diagram was a
one-pager, photocopy of poor resolution. However, I can get around this with
the good diagrams available from other sources along with my earlier experience.
Larry is honest and stands by his word. Enough said. 

Bob, Jim: If you have not already done so, might I suggest you get a copy of
the Wiring Diagrams made by Coventry Auto Components. While there may be other
sources out there providing equal quality, Coventry's slim volumes are by far
the best I have found yet. Their address is:
CAC Ltd., Unit 4 Portway Close 
Off Torrington Avenue
Coventry CV4 9UY
Ph.# (01203) 471217
Fax # (01203) 421123
It migt be stretching to say "enjoy", but best regards anyway. Klaus

Mar 1997, from: Bob Hardison: I've been lurking and listening to the thread on
rewiring one of the beasts. Does any one have a nominal time required by a
professional garage (knows what they are doing) to do the job on a 140 DHC,
manual OD, factory foglights? I only need the time, as I am providing the
harness, connectors, wiring diagram, etc. 

4 Mar 1997, from: Neil Skipper: Arno, I am interested in your experience. How
much did you pay for the complete wiring harnes? One of the notes talked about
wires having plastic coating wrapped with cloth. Was this your experience?
Thanks, Neil

5 Mar 1997: Neil, My experience with Auto Sparks was very good. The wiring
harness looked exactly identical to that, what I had to cut out of the XK. The
color codes were as original, referring to the width of stripes, thickness of
wire and insulation. To your question, whether there was hidden plastic covered
up in braided cotton: There was no plastic covered up at all. Everything looked
to me like the original. John, is there a chance, that those guys were
original suppliers? Ref. to the price I paid, I have no idea any longer, that
means it must not have been that much, because if I would have felt being taken,
the price would have been branded in my memories. Someone should give Auto
Sparks a call and ask. Arno Wahl

4 Mar 1997, From: Donald L. Sime: The recent thread about rewiring an xk
reminded me of the rewiring of my 150 fhc that I did a few years ago. It was
not as much of a problem as I thought it would be. I had really been afraid of
starting it, thinking that I would end up with wires all over the place and
nothing working. It went pretty smoothly and I learned a few things that might

1. You will probably have trouble finding a wiring diagram that is accurate for
your car. I found at least 3 that should have applied to my car, but all were
different. Find one that appears to be close to yours and stick with it.
Preferably find one that is larger than 8 1/2 by 11. The print gets awfully
small, especially trying to read the color codes for the wires.

2. You will need two types of continuity testers. One with a 12 volt light
that you can use to check if a wire is hot, and one with a double A battery in
the handle that you can use to find the other end of a wire, i.e. you put the
clip on one end of the wire and then poke the other end and if it lights up you
know you are dealing with the same wire. This becomes important when you have a
group of wires and can't match up the ends. You will also need a 4 foot wire
with alligator clips at both ends to use to extend the reach of your two
continuity testers.

3. Don't just tear out your old wires and throw them away. Very carefully
remove each wire and draw a diagram of what you are removing. Check it against
the wiring diagram. For example, at the ammeter there are several wires that
come in and then go to somewhere else. It will make things a lot easier if you
have mapped out the way it was. The same is true for the other instruments and
the fuse box and turn signal relay. Your present wiring may not be original, but
don't be too fast to tear it out. If the wires all work, it is nice to know the
way they were when it last worked. 

4. Take each item one by one. For example, take an item from the source of
power all the way to the end where the power is used. Don't hook up everything
at the front of the car i.e. lights, horn and then try to hook up the other end
of those items. Hook up the headlights from power to switch to lights, then the
side lights from power to switch to lights, etc. 

5. There will be areas where the wires run through the body channels which will
be impossible to feed a wire through it. Identify these areas and then pull the
new wire through as you pull the old wire out. This is really more difficult to
explain than it is to do. Just take your time and plan ahead. It is a good
winter project, I did my 150 in about a month of part time work. About a week of
that time was spent analyzing how the wires were before I pulled any out.

6. Working behind the fascia is hard. Your hands are going to be too big for
the small space. I recommend you remove the fascia (in the 150 it is three
pieces: right, left, and center) and the glare shield (I don't know the proper
name for it). It will give you access to all the wiring from above which helps

7. I got my harness from Welch Jaguar and was satisfied with it. They will ask
you all kinds of questions like: do you have overdrive, auto trans, etc. Then
when you get the harness it will probably have those hook ups anyway. You can
always cut them off but DON'T, at least not until you are sure you don't need
them (I saved mine anyway and used them for some other electrical connections).
Don't be surprised if you end up with a few extra wires that you can't figure
out what they are for. I still have a few that I can't explain.

If you attack the job in a methodical manner and document what you do, it is
actually a lot of fun. Believe it or not, there is a system that Jaguar used
that makes sense (surprise). Once you are done, you have the benefit of knowing
where all the wires went and how to verify it is not the wiring that is causing
the problem. Don Sime XK150 FHC.

30 Apr 97, from Lee Eggers: British wiring offers very nice and authentic
harness at a reasonable price. For idiot proof directions and higher prices
check with Rhode Island

30 Apr 1997, from: Ed Mellinger: As usual, no Jag experience, but I'll bet that
British Wiring at 708-481-9050 (Illinois, USA) would be worth a call. I bought
a harness for an old motorcycle and was impressed with the materials and
construction; they can supply the cloth covered wire, etc., if you want. There
were a few inaccuracies (i.e. they used the wrong schematic) but they were very
helpful about making good on their product (which they import from Merrie Olde
England). I'll probably use them again, but I'll have a more careful dialog
about what they are supplying vs what I need.

30 Apr 1997: My vote both for authenticity, good installation diagrams and
pleasant people goes to Rhode Island Wiring, 800-777-4947. I've used them for
two 120s and most of an E-type. Dick Cavicke

1 May 1997, from: Dick Rowley: Adding a "second" to RI Wiring. They aren't the
cheapest but I put theirs in my Healey 3000 and it matched up perfectly-
lengths, connections, material, etc. Very good looking in the car. Rowley '54

2 May 1997, from Robert Oates: Can't speak about British Wiring folks, but as
Lee said Rhode Island Wiring Service is higher priced with excellent schematics.
I supplemented the Rhode Island Wiring schematics with an excellent wiring
diagram / booklet from XKs Unlimited. Unless one is a bumbling fool on rewiring
work, these references are bullet proof. Good luck. 

1 May 1997, from: Klaus Nielsen: Coventry Auto Components Ltd. sells excellent
and highly detailed wiring diagrams for virtually every XK model. Great value
for the money. 
CACL, Unit 4, Portway Close, Torrington Ave, Coventry CV4 9UY
Phone 1203 471217 (24 Hours), Fax 1203 421123

If you have any questions or comments send e-mail to:
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