Packard Forum Index » Post-War (1946-54)

Hi all, Howard; In my last post, I was going to test out some 51-53 fuel gauges for a Buddy. I did recieve the Amazon voltage reducer, and I have five gauges to test.

After looking at the gauges one is from a 48-50. After comparing diameter,depth etc.....these are the exact same size KS as the 51-53. Even the face is similar on the 51-53 but could be removed and swapped with the 48-49.

Why don't people make this swap, then change the sending unit,to a more popular and easy to find straight resistance type sender 10 -75 ohms, and make this whole expensive thermal type sender go away?.

My best guess, the cost of parts,$120.00, labor $ priceless.

Just an idea.
Dave O.

An interesting idea and if it works maybe a possibility for temp and oil gauges also. Would need either a stock 51-4 instrument voltage regulator or something along the lines of the Amazon item that would accept a 6v input to be added to the 48-50 but that is doable. The lack of "flite glo" paint on the later needles might be an issue so a solution would need to be found for that. Before committing to something like a conversion it would also be a good idea to get in touch with KM Lifestyles and verify for sure whether or not they have or can make a sender for the 48-50 gauges. I don't recall anyone ever having mentioned them making one but I don't know if anyone has tried or they definitely do not. Even if there is a fuel sender available it still might be a possibility for oil and temp gauges because those senders seem to be getting just as scarce.

If you have an ohmmeter it would be interesting to know the resistance range of the heater in the older gauge vs the newer and just for curiosity what the later sender has the gauge read when used on the older gauge. An issue might be the older senders use screws to mount the sender to the tank vs the small thin flange and twist ring on the 51-6 senders so that would need to be addressed. Possibly that could be with use of one of the modern universal senders that can be modified to fit various depth tanks and usually have the screw mount flanges.

As I recall, Packard uses a different size or number of screws in their mount and one fellow who tried a modern sender with an old gauge (didn't work) had to buy a conversion flange along with the sender so sender would fit the Packard tank. When his first attempt did not work he converted to a set of Classic Instrument modern gauges which are different but still somewhat similar enough in looks to the old they are not too visually jarring in the dash.

If the substitution of gauges does work then it would be a matter of convincing the purists the modification to something non stock is a viable option and then finding someone wanting a sideline to do the work. Changing the entire gauge might be something those who have limited mechanical skills or those who are not able to work with precision around small and delicate items might attempt but I think It would be a hard sell for them to want to do the delicate work in changing the faces themselves.

Thanks Howard. I'll be the genipig. I already purchased an after market fuel sender and matching gauge to install under the dash of my 50 for up coming driving season.

However in the winter of 22-23, if we're all still alive?. My plan was to pull the dash and rewire it. My buddy said I can keep one of the fuel gauges for the 51-53 as long as he has one good one for himself. I will install the 52 gauge in my 50, purchase another sender, for 10-75 Ohms,make an adapter plate to tank, and test it out, bench first! Then install.

From what I read last night, I believe the instrument regulator voltage reduction is the same for 1948-1950 as the 51-54. Unless I find find any other articles saying different.

I'll give it a try, but it won't be for another 9 months.

Thanks again: any other issues you can think of, please let me know.

All gauges prior to 1951 24th series are connected directly to straight battery voltage so between 6.3 and roughly 7.4v depending on what the main voltage regulator has the generator outputting. It might be interesting to see what the 48-50 gauge would do with the later sender if it was supplied a regulated 5v via the instrument regulator or power supply.

Interesting idea. Since your knowledge of electrical systems is much better than mine, in fact I hate dealing with electrical stuff! Your correction on gauge voltage has given me another idea.

I didn't want to be messing around under the dash this summer as the wiring looked pretty rotten and I really want to drive it. However......


Since I may have a free 51 Gauge soon. I could try to send back the aftermarket gauge/sender I purchased. I could tap into instrument power, add the regulator run the wire to the 52 gauge, make a bracket so I can mount it under the dash, ground the gauge.

Buy a universal sender with proper Ohm rating for the 52, classic instruments makes one, they say for early Fords but it doesn't matter has long as the Ohms are a match for the gauge.

Then I only have to make sender Adapter to tank plate. I could be testing this all summer. I really think this has a good chance of working correctly.

Dave.

Most gauges 47 and earlier do need a ground because they are the magnetic type with 2 wound electromagnet coils inside to move the needle. One of those coils needs the ground and the other coil gets the sender wire. 22nd and later series gauges are the heater operated bimetal type and do not need to be grounded because the heater is wired between the two terminals. Only the regulators on the years that had a regulator need a ground so that might help with your under dash mount

I posted this comment to a duplicate post. Why not delete the extra while you can? Here is my comment again.

There are also senders that look like the 1948-1950 but are actually for the 1951-1954 Henney-Packard commercial chassis and work the same as those on the passenger cars of those years. I have one out now being rebuilt so had to make that detail very clear to the rebuilder!

Well Ive spent most of last night and today researching old posts from this site, Packard club.org, the Ford Barn, and internet in general. I am less confused but only have one definitive answer.

Fred Kanter posted on 5/19 2017:
If it were just the matter of a resistor it would have been figured out already. Unless you use a 51-56 sending unit, tiny voltage regulator, and 51-56 style gauge there is no option except to repair your 48-50 unit.

Parcial artical I found states: The service training book for 1951 descibes a new style sender with compressive resistance disc's

6/20/21 51-56 senders which are of straight change in resistance type.

I am guessing the straight resistance type to be a substitue for the bimetal, but I believe the points and heating coil are still there.

Howard, I called KS they don't make anything for King Seely.

Currently I feel the safest going with Fred Kanter's reply. So I'll look for a good senting unit 51-54.

I wish I knew for sure if the after market units like Napa, Spectrum, Classic Car do work propery. Many members say they fit and work. However know one seems to write in when they fail, or how long it took, or its still working after 5 years. Maybe some members can give me an answer. A lot have said the dial was off. I just wonder if theses units have the heating coil, and contacts for $70.00?

Best Wishes;
Dave

The bimetal operation is unique and as far as I know only used for a couple of years by some Ford products, Packard and a couple of others. Good to know you did confirm it is not available.

I did some experimenting with one several years ago and captured the operation on an oscilloscope. I am not familiar with a compressive disc type sender and don't believe Packard used what I would consider compressive discs like the stacked tablet like carbon disc resistance such as used in some 1949-50 heater switches.

The universal Ford straight resistance 78-10 ohm senders do work but they need to be modified. Some stock Ford units of the mid 50s work as is but you do need to make sure the tank depth and length of float arm is the same. Ford had several model senders for their various size tanks. Before Kanter repro'd the 51-6 senders I experimented with one of the universals and following instructions that came with the sender to adjust the float, made other modifications to mount the universal sender on an original sender flange so I could install it in my 56.packardinfo.com/xoops/html/downloads/56fuelsender.pdf

(Note that the part numbers and price of the Universal sender I used and quoted in the article is no longer accurate.)

Attach file:

---

  22-23 bimetal sender action.jpg (149.87 KB)

The one for 1957 Thunderbird and a number of other Fords of the era is a direct fit. You may need to adjust the float height but that’s about it.