I've been searching the HAMB and Ford Barn, trying to find a temp sending unit that I can buy at the local NAPA or O'Reilly, that has the correct resistance to work with my 1940 Ford temp gauge. I'm not interested in spending $40 + shipping to the antique auto specialty places if I can spend $15 at the local parts house. I've tried two, so far, and haven't had success. One I tried was supposedly for a '66 mustang, and about 2200 other Ford varieties, but it just kept the needle buried in the "cold" side. I changed it to a BWT WT127, which is equivalent to the NAPA MPETS6178SB. Still buried the gauge in the cold side. I figured I may have my gauge wired backwards, so I swapped sides with the power and the sending unit, but no change. I had gotten the NAPA part number from this thread, on the HAMB: http://www.jalopyjournal.com/forum/threads/1950-ford-f2-gauge-question.202345/ I'd be thankful if someone can pass along the correct resistance that I am needing to find a sender for, or a known part number for a compatible sender. Thanks!
So you are out 30 bucks and you still need the 40 dollar sender. Electrical gauges need the correct senders.
the only place I have ever found a replacement sender was from a catalog, for example Macs or LMC, and those are usually iffy in quality. you can find original old ford sending units on eBay..... sometimes. local auto parts stores?....good luck.
I doubt your going to find what you need at any of your local auto parts house. Just order what you need. HRP
I'm trying to post this politely, I am continually baffled by the number of posters on web forums that think that the local auto parts store can provide parts for a car that is 50 or more years old and be cheap. That is not the case, it might be nice just to pop down to the corner parts store but all they say is let's see what the computer says. In most cases the local auto parts store doesnt have the knowledge or access to obsolete parts like the specialty stores do. The other day a customer need a specific grease seal, The local N--- had it special order for $42.00 it was in stock at the specialty store for $$18.50. If you have a 40 Ford you should be dealing with a specialty store that knows about your vehicle not the local parts replacer. You might think t he parts might cost slightly more but the value of access to information is far greater than the cost of the part. You need temp senders for your 40, in stock, new old stock parts even,
Wow...I know that this might baffle some, but that's kinda how this whole "hot rod" thing goes. Using some parts from a different source than OEM for the vehicle the hot rodder is working on. In my case, I'm trying to find a substitute to make my temp gauge give me an idea if I am hot or cold. If it was a restored car, running a flatty, sure, I would probably consider buying NOS sending units. In my case, it's running a Chevy small block. For the record, I have an oil pressure sending unit, from the local "parts replacer" that works great with the stock '40 gauge. Because the gauge only reads up to 50#, I used a OP sender that is rated at 90#. I've referenced it against a mechanical gauge, and am comfortable with estimating approximately 2x what the gauge reads. It's not rocket surgery. Gauges don't care whether they are 40 Ford specific, they care about the resistance. Ford didn't change the resistance values every year, just to ensure that he could sell more sending units. I'm sure that there is a newer part number that has similar ranges to what the stock gauge is looking for. Tommy, at this point, I'm out a total of about $15. All is not lost yet. ;-)
The 40 Ford temperature gauge works on the bi-metallic principle of heat conduction in both the gauge and the sending unit. It DOES NOT work on the principle of straight linear resistance of ohms. The OEM senders were made by King Seally and were used up into the early 50's. By the time you spend $$ buying experimental sending units it would have been cheaper to just spent the big bucks for the correct sender. Also, local swap meets might be a lucky source for a good used sender.
I understand what you are trying to do and have done it many times myself. Many times the "specialty" parts are available at the local parts house. But I think you have too many variables going. Does it matter if it's 6v or 12v. Did you fry the gauge by swapping the wires? What is the original resistance and range? Here's an example from the illustration of your 66 mustang unit. If you know what you need the book may help.
Gauge is still good. Nothing fried. I'm using a 7806 voltage regulator, to drop from 12v to 6v. I don't need it to be precise, I just need to have an idea of where my normal operating temp is, so that if/when it exceeds that reading, I know I've got an issue.
Whoa sorry I jumped on you, where in the original post did you state that you were running a 12V SBC.
Important info that I neglected to have in the opening post. Forgot folks can't read minds on here. ;-) I'm running a SBC, 12v, and I am using the home built 7806 voltage regulators on each gauge. Stock sending unit on fuel gauge. Oil Pressure gauge with a BWD S330 sending unit (stamped 90#) which reads 1/2 of what the mechanical aftermarket gauge read, and was trying a sending unit listed above, and also the BWD WT127, which goes back to 1963 Ford vehicles, with the thought that FoMoCo ran 6 volt gauges and more than likely didn't change the resistance in the sending units. Obviously, that was not a correct thought. I've got a single pole flathead sending unit, somewhere around here, just can't find it at the moment.
The old temp gauges are basically a thin wire(heater) wrapped around a bimetallic pointer actuator. They will not be sensitive to being wired backwards. They are also set up with a reverse resistance curve. No current the pointer is at hot. More current/more heat moves the pointer to cold. What you needed to determine is are resistance values to move the pointer to cold, normal and hot. The Mustang sender resistance numbers are reverse to what the gauge unit expects. If the parts books show a unit with low resistance at cold and high resistance at hot it will most likely work. The new specialty replacements are not the original vibrator design. The are solid state utilizing a reverse temp curve thermistor. I took one apart to find out why it was intermittent. It had a bad solder joint. Fixed that and it works full time. Sorry for the long verbiage.
There's another option here-leave your stock gauges alone and add a modern 12volt old looking under dash three gauge set in a nice little chrome panel-no more guess work and a 'traditional' modification.
Asphalt Angel, that's exactly what I what I was trying to get away from. I had mechanical oil and temp gauges mounted by my kick panel, and was finally trying to migrate to the actual Ford gauges. Sounds like, based on what Forty1FordPickup has contributed to the discussion, a modern sender isn't gonna be an option, unless I can find the resistance range of what the gauge wants and can find a list of specs of modern senders. Was hoping that someone had already discovered if that option existed.
One solution is to get a temp gauge/ sender out of a 70-80's Ford truck. The movement will fit into your stock '41 gauge case( looks stock), install the temp sender on the engine and you're ready to go. Can get a replacement sender, if needed, at any local parts store. Make sure you have 6V to power the gauge.
I think it was R&C. I remember closing the pop up ad with Jimmy Hervatin's little green truck. I stumbled across it in my many searches looking for info. 54fierro, what book did ya scan that info from? Was that one of the secret books that they keep on the back shelf in the local replacement part store? I may have to get the flatty powered truck out of the garage, and take some readings with the multimeter, and see if I can find anything in the book that has the resistance numbers in the similar ranges. I'm not opposed to using a flathead era sender, and I have one around here, somewhere, but it's always nice to have an option.
My first engine trans plant at age 17 was a 63 383 into a 58 Ply. I thought Chrysler corp product, 5years apart, both 12/v It should work fine. I chased and spent a lot of money on a running hot issue. Finally I pulled out the 58 sending unit and put it in my 63 engine and discovered I did not have a running hot issue but just a sending unit issue. Always use a sender that is engineered for your gauge. Saving a few bucks to use a "maybe it will work" sender is not worth it IMHO It cost me a lot of money to find this out I bought Imperial radiators, fans and all the cooling ideas of the time. Changed the sending unit and it was just fine all a long. An expensive lesson that will never be forgotten.
I had to do some digging, in the garage cabinet, but finally found the "flathead" temp sending unit. Resistance is basically 0 at the "cold" setting, and after soaking in some hot water, at roughly 170 degrees, was around 37 ohms. That is the kind of info that I was looking for, so that I could run up to the parts store and dig through their book. They may, or may not, have something in it that would be similar, but it's worth researching and documenting.
If that is an original vibrator type sender the resistance values will fool you. If you can find a 35 to 40 ohm resistor. Hook that up to the gauge to see if it indicates in the normal range. It is cheaper to do than buying another sender that might not work.
The one that I have has the King Seally logo, with a 0 (zero) stamped below it. On the opposite side, it has 224 stamped. My guess would be the 224 to indicate that to be "HOT" temperature. Anyway...I know what my plans are, for after work tonight.
Yes from the super secret parts catalog. These are probably the books that normally got chucked. It's the buyers guide from Standard Ignition. I will post a pic of the part numbers along with the specs in a bit. Maybe be of some help for future reference.
Ok, Guys... I realize this is a very old thread, and I've read this one twice, but it doesn't answer a question I have about my shoebox temperature gauge/temperature sending unit. 12v/6v reducer driving all the gauges except Ammeter. Got the first sensor from Shoebox Central .... it worked for a while but read "high" on the gauge, nearly full hot, when the thermometer on my radiator (return water temp after the radiator) of 160 degrees, so I know my sbc isn't running hot. A couple of weeks ago, when I cranked her up, the gauge stayed on "full hot" and never moved. Sooo, I bought another sending unit "American made", proper for the car. (6v, 49-51 ford), installed it and it works fine EXCEPT it's showing the same as the first sending unit before it died, that is, showing just a tad below the "super hot" indicator on the dash gauge, when it is NOT hot. Here is the question. Can one do anything to compensate the reading so that at "normal" temperatures it settles in at about mid gauge???? If that dang dash gauge sits there on "hot" all the time, I won't know when it's REALLY hot..!! Thanks in advance.
That is how the King Seally reads in my coupe. I did install one that I got from Mid-Fifty, in the 40 MorDor sedan, and it read correctly. At $50-60/each, it gets kind of expensive to test and try multiple senders.
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