Simplified S1 4.2 OTS colour wiring diagram

Hi,
Since I could never find a schematic colour wiring diagram I decided to draw my own.
UPDATED June 4, 2018. Thanks @davidxk for the correction!


“Attribution-NonCommercial”: Feel free to make copies for non-commercial use but recognize the author.
Correct to the best of my knowledge for my S1 1964 4.2 OTS. The author will not be responsible for any
liabilities, losses, or damages arising out of the use of the information provided. Adapt to your vehicle. Feedback and corrections welcome!
Regards, Vince
vincent.disselkoen@gmail.com

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The diagram is terrible!!! It is so logical and easy to use that people won’t have to rely on me to help them with electrical issues!

GENERATIONS OF GRANDCHILDREN WHO INHERIT OUR CARS WILL THANK YOU!

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Well done Vince,
Wish I had one like that when I did my 67 FHC. In the end, I replaced my harnesses one by one.
Regards
Chris

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Vincent,

Looks like a great improvement on the fuzzy version in the Bentley manual for your model year (1965) though I see yours was manufactured in Dec 1964. One possible error in the top RH corner. You show the oil pressure switch as feeding into the same RG line as the handbrake and brake fluid level warning circuit. As far as I know the oil pressure switch was connected by a NB wire to the ignition warning lamp in the speedometer for that model year, prior to the introduction of the 3AW that used the alternator AL output.Thanks for publishing this - it will no doubt help those with similar era cars.

-David

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Thanks David.
Eagle eyed. I stand corrected. Hadn’t spotted that and I never saw an original wiring diagram with exactly that configuration, since the manuals I know all seem to skip the very early 4.2’s wiring. But than that was the reason for drawing this simplified version in the first place :slight_smile:
Will do some measurements when I have the dash top off and correct the info.
Kind regards, Vince

Vincent,

I’ll send via private message the pdf I have of early 4.2L Series 1 cars. It’s fuzzy, but does show the oil pressure switch that lights the “ignition” light in the speedo. It should give you something to cross-check your diagram against.

-David

Thank you Vincent!! I am just getting into sorting out the wiring on my early (Nov 64) 65 4.2 Roadster and you’ve made my day. It is obvious that you spent some time on that diagram.
davidxk: I’d would greatly appreciate a look at that fuzzy pdf you mentioned with the oil pressure switch correction.

Hi @davidxk, I updated my simplified diagram. The version you sent is also the one in my manuals and is correct for my very early 4.2, but I’m still surprised that the early 4.2s are explicitly out of the range of both diagram versions… Regards, Vince

Vincent,

This statement has me confused. It appears to contradict itself. What “early 4.2s” are out of the range of both diagram versions? You are not, perhaps, interpretting the Legend in the diagram I sent you (page P.X.s.28 of Bentley) literally, which is clearly wrong and very confusing as in the “From” part of the covered range it only lists 2+2s (LHD&RHD), and the “To” part only lists LHD models (OTS, FHC & 2.2). In my ranges below, I’ve put in bold the car numbers mentioned in the Legend of the first diagram, and in plain text those that I believe should also be there, but are missing (maybe because the author thought the were obvious? My assumption is that the diagram is intended to cover all 4.2s from:
1E.1001 (RHD OTS)
1E.10001 (LHD OTS) including the early cars missing the 1E prefix
1E.20001 (RHD FHC) including the early cars missing the 1E prefix
1E.30001 (LHD FHC) including the early cars missing the 1E prefix
1E.50001 (RHD 2+2)
1E.75001 (LHD 2+2)
to:
1E.2036 (RHD OTS)
1E.15979 (LHD OTS USA) and 1E.16009 (LHD OTS non-USA)
1E.21785 (RHD FHC)
1E.34582 (LHD FHC USA) and 1E. 34751 (LHD FHC non-USA)
1E.51196 (RHD 2+2)
1E.77708 (LHD 2+2)
The diagram on page P.X.s.29 covers all models after the “to” numbers listed above.

NOTE: there is a minor discrepancy in the legends of the Jaguar diagrams in that car 1E.77709 in included in the range for both diagrams. I believe that the first diagram range should end at 1E.77708 (ref Clausager)

-David

I also have an early 4.2 S1 with a manufacture date of October 1964; serial #10275. I agree it is difficult to decipher various wiring schematics to come up with correct connections. I am in the midst now of cleaning the dash instruments and every time I look at the wiring diagrams I have (Bentley, Haines & one specific to 4.2’s from XK’s) I become more confused trying to reconcile those connections to my wiring loom. To this end I would very much appreciate if you could link me in to your pdf on your wiring schematic. Also, any pictures are also appreciated. Thanks very much in advance.

Stephenc,

Earlier in this thread I think I may have caused some confusion by referencing a fuzzy pdf wiring diagram (page P.X.s.28) for the earlier Series 1 4.2L cars. I found it on the JDHT CD Rom which contains the Service Manual and Parts Lists. In most respects, the Service Manual part of this CDRom is identical to the green Bentley Manual, which itself is a reprint of the Jaguar Service Manuals. The reason that I mentioned the diagram from the CDRom was that it was not present in my Bentley manual. Therefore, when the original poster (Vincent) mentioned that he was having trouble finding a wiring diagram that accurately reflected his early 4.2L car, and had produced his own, I concluded that P.X.s.28 is missing from all Bentley manuals. I therefore offered to send him a copy as a cross-check. However, Vincent has recently indicated that the document I sent him (P.X.s.28) is in his Bentley. Therefore, it appears that I was wrong in concluding that P.X.s.28 is missing from Bentley in general. It is a problem with my copy. In hindsight, I should have suspected this, as I’ve noticed other page(s) missing from my copy in the past. I must have a bad printing. So, unfortunately, I have nothing “new” to offer. As far as I know, the diagram on page P.X.s.28 IS the diagram for all Series 1 4.2 cars from the early 1965 models (some of which were manufactured in 1964) up to the demarcation point identified in the legend (which is itself confusing - see my earlier post). Unfortunately the diagram is somewhat fuzzy, and tries to cover all the variation from early to later cars in the same diagram (e.g. both methods of driving the IGN warning light). What I understand Vincent has done with his new diagram is (a) make it much more usable by showing the wires in color, and (b) make it specific to the “early” 4.2L cars by eliminating the variations that came with the later cars. His benchmark for this exercise has been the wiring on his own car. Without some research I can’t comment on the range of car numbers it would be accurate for. I hope that this clarifies my understanding of what wiring diagrams are available for the Series 1 4.2L cars. If anyone thinks I have got it wrong, please comment. My objective is for the contents of this forum to be as accurate as possible, so that others can make use of the archives in future as our collective memories fade…

-David

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Hi @davidxk, I agree that the ranges you added in normal type probably should have been included in the original legend of the 4.2 wiring diagram, including our 1E10xxx. That would solve the mystery of the missing pages in both my Bentley binder and my Haynes manual. So far I found no discrepancies. My diagram is thus a reorganised version of the “fuzzy” one (in print quality and organisation) where I excised the electrics absent from a 1964 4.2 manual OTS.
Regards, Vince

New version, slightly slimmed and with workings of the panel switches visible since I couldn’t recognise the three positions in the manuals.


Sorry for the reply instead of an overwrite - I seem to have gone over the editing grace period and can’t update the original.

Wow, fantastic. Do you know if there is much different from my 1964 3.8?

Excellent! Now c’mon Vincent, be a sport and do one for the S1.5…:slight_smile:

Honestly, from what I saw of the wiring diagrams I can’t find any functional differences between negative earth 3.8 or 4.2 OTSs. There are, of course, different connectors or routes of wiring in the same colour (because of LHD/RHD, or the placement of horns, for example). Oh, and the fan relay. Even the oil pressure warning light wiring is the same, as spotted by guru @davidxk, whom I invite to corroborate or disprove the above :wink:
Wiring looms are different, of course: see https://www.angloparts.com/en/catalogues/group/4390/e-type-wiring-looms-cables-lhd-cars-only.
3.8 owners: Corrections welcome!

If there were 6726 S1.5s produced, aren’t there 6726 variants of the wiring diagram :wink:?
But good point - hard enough to find the correct wiring diagrams for S1 and S2 by VIN number, also see @davidxk’s comment above. If the Bentley manual is to believed, and given that according to http://jagxketype.ning.com/page/etype-s1-s3-serial-production the S1.5 VIN started from
OTS RHD: 1E/1864
OTS LHD: 1E/15980
FHC RHD: 1E/21584
FHC LHD: 1E/34583
2+2 RHD: 1E/50975
2+2 LHD: 1E/77709 (not -8 as David and jagxketype say)
the diagram for early cars (matching my simplified version) would be correct for the OTS RHD but not for the other body types, which would be rather strange. So I fear we’d have to do a S2 version to best satisfy your request…