120 fhc gauge question

I am in the process of building the instrument panel for my 120 FHC and have some questions about the gauges.

This is a ‘parts is parts’ car so the parts, including the gauges, were gathered from multiple locations so are not original to this car. I sent all the gauges to Nisonger for overhaul, and am very happy with the quality of what I got back, but am running into a couple of problems with two of the gauges.

The first problem is the petrol gauge. There something out of kilter as the housing has the proper location for the low fuel light bulb, but the gauge face does not have the lens that the light shines through. Also, the part number on the face is x49422/202, and I think it should be x49422/157 . The issue is not that it may be from the wrong model, but that I don’t understand how you can have the correct housing but an incorrect face. Can’t imagine why there would be a gauge with provision for a light bulb, but no where to shine it through.

The second issue is a similar one. In this case it’s the oil pressure/water temp gauge. Same type of problem. The gauge itself has the proper part number, x42638/6, but the housing does not have the double flange on the outside, nor any slots for the panel lights to shine through, as well as having two mounting tabs, which I think may be a 150 style.

Looking for any suggestions of what I may have.

Jim

Petrol gauge - the light bulb lights up a yellow dot in the face, meaning that you are low on fuel.
Oil/Water - on previous models such as the Mark V, the gauges were lit up by lights located under the dashboard mirror support but above the gauges, so there were no windows in the side of the gauge housing.

Thanks Bob,

That’s the problem on the petrol gauge. There’s no yellow dot in the face, but there is the receptacle in the housing for a bulb, so nowhere for the light to shine through.

Sounds like the Oil/pressure gauge housing might be from something like a Mark V, but why would it have the part number of a 120?

Can you post a picture of the back of the gauge?

Eric

And the front face, maybe we will recognize it.
Here is the one in my 120.

Here is a Mark V. Note the squarish characters only used on Mark V.
PICT0016

PICT0003

And here is a '38 SS which did not have a low level light.

Here are pictures of the two gauges in question


Face view of gauge X42638/6

Back view of same gauge. You can see here that there are no lighting windows around the outside, as well as no second mounting ring. Also has the two mounting tabs.
Back of Petrol gauge. Can see that the low fuel light mount is present.
Front of Petrol gauge. No window at bottom for warning light to shine through.Showing part number X49422/202

Well, those are the correct part numbers. Looks like two mistakes by Nisonger’s. Wrong case on one and wrong face but correct number on the other.

That’s kind of the same conclusion I came to, but I called Nisonger with that question and was assured that the technicians were extremely cautious about keeping all the components together. Unfortunately, this was done over a year ago, so any warranty is not valid anyway. Might have been able to do something about it if I had noticed the issue when I received them. My plan right now is to disassemble the gauges and make the modifications necessary to make them functional. Other things I’d rather be working on, but it can be done.

my 1953 120 fhc

Phil,
Can you advise Chassis Number of your FHC.
Your Instrument Panel is the earlier arrangement, thus not as expected for a ‘1953’ FHC, so presumably a marketing/sales 1953 reference, and not actual date-of-manufacture.

Thus also the pictured PETROL & OIL combined gauge, rather than the later XK120 PETROL only gauge.

Over the XK120 period there were the two Petrol Gauges;-
Initially from the start, a C.2776 which was a SMITHS X.49422/157 which was a PETROL&OIL level dual gauge.

From October 1952 dom, the later C.7131 superseded which was a SMITHS X.49422/202 now a PETROL only gauge.

And then from the introduction of the XK140 model in Oct 1954 the C.8415 superseded, being a SMITHS X.49422/230 still a PETROL only gauge, but now with an added low-level warning light, as per following photo…

My car details at on xk data. I’m not near my confuser at the moment.

Question.
Does the post October 1952 wiring diagram show with or without low-level light as now I am totally confused.
Are OTS and FHC different?
Images in ‘Jaguar XK120 Authenticity Reference Guide’ page 96 suggests both early and late 120 gauges with light. Not how I understood it to be or how described above.
Also light shown on the later gauge again on page 93.
So which is it? Please.
Regards, Graham

Graham I can only offer my experience… my '54 OTS has the low level light … ask me how I know :wink:

And then it would appear there is number three fuel gauge X.49422/202 WITH low-level warning light.
Is this possibly the change referred to around March '54?
(just in view on the left)

Notice also that it is labelled ‘SMITHS MA’ and not just SMITHS as the X.49422/230 from the 140 is.

To the best of my knowledge and resercah into this; there were TWO only PETROL GAUGES ever used in XK120, and then a THIRD Gauge introduced with the XK140, being the sole gauge used by XK140.

The first Gauge was Jaguar Part No. C.2776 which was a SMITHS X.49422/157 which was a dual PETROL & OIL gauge, exactly as per the earlier photo provided by Phil. According to the XK120 SPC this C.2776 gauge was fitted at up to all XK120s, at LEAST up to 661025/ 672942 (OTS) and 669002/ 680109 (FHC), plus six later cars which takes us up to at LEAST the end of September 1952.
The SPC clearly describes the C.2776 as GAUGE, Petrol and Oil Level complete with Warning Light, and if you look closely at Phil’s photo you can see the lens for the low-fuel level warning light just past the half way graduation on the scale.
The SPC is not clear about whether the C.2776 gauge was still fitted or not to the next revised Instrument Panel Assembly for all XK120s up to 661166/ 675207 (OTS) and FHC to 669138/ 681419, so up to March 1954.
The third revised Instrument Panel assembly does include the second Petrol Gauge the C.7131 or SMITHS X.49422/202 which is now a PETROL only gauge, but it still includes a low-fuel level warning light, which was what Phil queried originally with his second photo. Cant explain Phils /202 Gauge not having any warning light lens, so makes me think it has a reproduction dial face. Original /202 Gauges do have a similar lens as the /157. That takes us up to the last XK120, albeit I haven’t physically verified .

But I have physically verified several very early XK140s, and they all now have the next C.8415 Gauge - a SMITHS X.49422/230 - which has a more pronounced Lens for the Petrol Level Warning Light - as per photo I provided.

At this stage, the main loose end in this is to physically confirm whether Oct 1952 to Feb 1954 XK120s have the first /157 Gauge or the second /202 Gauge. Should not be all that hard to do, but would help to hear from anyone with Oct 1952 to Feb 1954 date-of-manufacture cars.

PS. A quick look at all the Lucas XK120 wiring diagrams will quickly confirm that all XK120 Petrol Gauges, most certainly did have a WARNING LIGHT built in.

In ‘Jaguar XK120 Authenticity Reference Guide’ it is noted that the illustration/text had NOT been totally verified by the authors. I am in the process of doing that now, but in this case as noted, the Petrol Gauge warning lights are correctly shown in all illustrations. But I am completely rewriting the text, to simplify it, and also ensure it is 100% correct - at the desired level of detail.

Roger

From

Roger:

My July, 1953 built XK120 DHC has a Smiths X.49422/202 fuel gauge with warning light and, to the best of my knowledge it is the original gauge.

Chris.

Thanks Roger.
The confusion arose from your previous post

“And then from the introduction of the XK140 model in Oct 1954 the C.8415 superseded, being a SMITHS X.49422/230 still a PETROL only gauge, but now with an added low-level warning light, as per following photo…”

implying the previous petrol only gauge, X.49422/202, did not.

That’s good and bad news for me. I now know I have the incorrect petrol gauge installed but do have the correct one in stock.
Cheers.

The J8 Spare Parts Catalogue does advise of course that the OIL LEVEL ELEMENT UNIT IN OIL SUMP was deleted, and a blanking plate fitted to the hole in the sump from Engine Number W6131 onwards (plus a few out of sequence numbers), and this does reasonably reliably coincide with the October 1952 date of the likely deletion of the first type PETROL & OIL level gauge. So although really I have no doubt as the very end of September 1952 being the demarcation date as per the quoted Instrument Panel 661025/ 672942/ 669002/ 680109 chassis numbers, it remains circumspect to verify the J8 SPC advice with known/original sightings.

So Chris’ advice re his July 1953 built DHC reinforces the J.8 SPC interpretation, given the Feb 1954 red-herring date (which actually applies to another detail of the different Instrument Panels - not the PETROL gauge).

There is a lot of confusion with all the Instrument Panel complexities, thus the current rewrite to make it simpler, but maintaining accuracy at the desired level of detail.