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Discussion Topic:
gas sending unit condenser?
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1937sedandelivery |
07-01-2017 @ 11:52 AM
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Senior
Posts: 501
Joined: Jul 2014
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Hello, On my 37 Fordor, I opened the little trap door in the trunk area to gain access to the gas gauge sending unit. Besides the single wire that feeds back to the gas gauge in the dash, there was what I think is a condenser. It has a single wire and is connected to the same point where the sending unit wire connects. Question: is this a condenser (see picture)and should this be installed here? It doesn't show up on any of the wiring diagrams I have. I understand a condenser is generally used to filter noise from a signal but I wouldn't expect much noise to be generated by the sending unit. What am I missing? Is this stock? Thanks, gregg
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ford38v8 |
07-01-2017 @ 12:12 PM
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Senior
Posts: 2764
Joined: Oct 2009
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Gregg, Not stock, but do you have a radio? Condensers were used, as you say, in some unusual places, some were effective, some not so much. With regard to your sending unit, you should replace the cork float with modern, as the modern ethanol removes the sh*llac that kept the float waterproof. Do not buy a modern sender unit, as they operate on a different principle that the original, and will never be accurate. Just clean up the old unit and reuse it.
Alan
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1937sedandelivery |
07-01-2017 @ 3:57 PM
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Senior
Posts: 501
Joined: Jul 2014
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Thanks Alan. The car does have a radio. No idea if it works, will tackle that later. If it ends up working but has lots of static I will try adding the condenser back in. For now, it will be left out. What a strange place to put one. The fuel gauge appears to be working now. Will swap out the float when I get a chance. Thanks for the tip on different sending unit types. In general, I don't like to use repro stuff. It always seems to be more cheaply made. gregg
This message was edited by 1937sedandelivery on 7-1-17 @ 9:35 PM
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Drbrown |
07-01-2017 @ 11:16 PM
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Senior
Posts: 570
Joined: Nov 2013
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Regarding the sender float, the OE sender unit in my '47 had a cork float that "sunk". I purchased a Bob Dake brass float bulb that snapped nicely into place on the OE wire float arm. Works great. If yours is similar set up, I can get their part # for your.
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1937sedandelivery |
07-02-2017 @ 8:31 AM
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Senior
Posts: 501
Joined: Jul 2014
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Thanks Drbrown. I will look to see what I can find on it. May come back to you. On a related note, I was perusing the Ford Barn Forum and ran across this comment on fuel sending units. If the signal is truly modulated and has frequency content to it, I can understand where it could show up as low frequency static in the radio. The condenser is designed to filter a specific range of frequencies so not sure is the one that was installed on my sending unit was effective or not. When I tackle the radio and it works I can experiment with condenser. "Like Jseery mentioned, the original sender and gauge operated on a FREQUENCY signal not voltage. The sender in the tank has a set of points that the gap gets changed by the float moving up and down. The gauge, is calibrated to read this FREQUENCY change and display accordingly. This is why a modern sender that is simply a voltage to ground signal will give readings that are not really accurate. I believe King Seely had a patent on this."
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MG |
07-02-2017 @ 1:45 PM
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Senior
Posts: 1260
Joined: Nov 2009
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Gregg - See this Ford Barn thread when its time for you to "swap out the float" on your sending unit > https://fordbarn.com/forum/showthread.php?t=190106&highlight=cork+float
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TomO |
07-03-2017 @ 10:00 AM
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Senior
Posts: 7256
Joined: Oct 2009
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I would coat your float with Seal-All. It is alcohol and gasoline resistant. The ethanol in the curren5t gasoline will cause your float to sink in a short time. Then you will have to dry it out in order to coat it. http://eclecticproducts.com/seal-all.html Tom
This message was edited by TomO on 7-3-17 @ 10:01 AM
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1937sedandelivery |
07-03-2017 @ 3:29 PM
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Senior
Posts: 501
Joined: Jul 2014
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Your help is invaluable. Thanks guys! gregg
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