Guest cattmann Posted August 10, 2011 Share Posted August 10, 2011 Looks like I need help from all you talanted people again. My gas gauge in My 1941 Royal decided to start acting up this past weekend. One minute it would be below empty and the next it would be past the full and then it would work properly. Now it sits below the empty.I have no idea where to start with this thing .If it were past the full I would probably look for a ground issue.I checked at the tank today with an ohm meter and have continuity If I am correct in saying so ,with the ground wire on the Tank.When I turn the key on I also have continuity placing the 2 probes on the 2 terminals on the tank..Thats it I have nothing else to offer.I have a repair manual but I am not one to follow electrical.Thanks Gary Link to comment Share on other sites More sharing options...
Joe Cocuzza Posted August 11, 2011 Share Posted August 11, 2011 Hi Gary,It could be that, if it is the original float mechanism, the cork float in the gas tank has started to absorb the gasoline and is now saturated and can no longer "float". What can happen thru the years is that the sealer used on the floats will break down and then the cork will become saturated and no longer function properly.As long as you have checked the ground/connections and are satisfied that they are not the problem, then the next best thing to do is pull the float mechanism and while it is out of the tank, you can check to see if it works properly by moving the arm thru the "full - to - empty" ranges and watch (or have someone else watch) the gauge in the dash to see what it is doing.You can inspect the cork float at that time, too.I believe that if it is the float you can get a replacement without too much hassle. I hope this helps.Joe Link to comment Share on other sites More sharing options...
Guest cattmann Posted August 11, 2011 Share Posted August 11, 2011 Joe I just came in from the garage .I ran a couple of tests to see if the guage in the dash works.I grounded the second wire on the sending unit to the sending unit and the guage went up to 7/8 ,which is as far as it ever goes when full. Secondly I ran a jumper from my ground to the second wire and got the same results so I guess my ground is ok.I removed the float and moving it up and down I get no signal to my guage. Sounds like I need a new unit maybe. Thanks for the help Link to comment Share on other sites More sharing options...
Joe Cocuzza Posted August 11, 2011 Share Posted August 11, 2011 Gary,I am not trying to be a smart*** (only trying to help) but when you removed the float mechanism and moved the arm up/down, did you have the housing of the mechanism grounded somewhere? You need to ground it otherwise you will not get a reading.Joe Link to comment Share on other sites More sharing options...
Guest cattmann Posted August 11, 2011 Share Posted August 11, 2011 Joe I definitley dont think your being a smart ass. Where I have 2 wires on the sending unit ,I assumed that it was self grounded. Link to comment Share on other sites More sharing options...
Joe Cocuzza Posted August 11, 2011 Share Posted August 11, 2011 I know on the later 1940's Chrysler cars, and I don't see why a 41 would be different, the housing of the float mechanism is grounded when it is bolted/screwed to the gas tank and the retaining ring is put on. So I usually take a wire lead with alligator clips and ground the mechanism, while it is out of the tank, to a bolt in the trunk. Then I check to see if it works.I believe that the 2 wire setup is - 1 is hot - feeds voltage to the mechanism / 2 sends a pulse signal to the gauge. So the grounding has to come from the housing.I hope all of this helps. I may not be 100% correct on every statement but I think I am pretty close.If I stand to be corrected, by anyone, just be nice about it. I never claimed to know all there is to know but I have had, and worked on, many Chryslers. I am going by memory here and sometimes, even though I am "only" 54 years old, there is always the chance of a brain fart here and there.Joe Link to comment Share on other sites More sharing options...
Guest cattmann Posted August 11, 2011 Share Posted August 11, 2011 (edited) Well Joe your 2 years younger than me and I will never say I know anything about these beasts.I am one to learn as I go.I did what you suggested with a ground wire and with the float removed it did drive my guage up.I found it very sensitive as to when it would stop before going up to 3/4 and full.I reinstalled the unit and powered it up. I probably had about 1/4 or less fuel in the tank so I put 10 canadian gallons in it and it is showing full even though it isnot as th manual says 17 gallons whether or not it is canadian or American I am not sure so what I will do is moniter it for a few days to see what happens.Not sure why it is workin now other than I might have gotten a better contact when I was fooling around.Any idea where this unit would pick up its ground?Thanks for the help as I really appreciate it . Edited August 11, 2011 by cattmann (see edit history) Link to comment Share on other sites More sharing options...
Rusty_OToole Posted August 11, 2011 Share Posted August 11, 2011 An erratic fault like you describe points to a bad wire, shorting out or not making a connection at all depending if you hit a bump or not or maybe how it feels that day. I would look for a loose or frayed wire, broken wire, crumbling insulation etc. Link to comment Share on other sites More sharing options...
Joe Cocuzza Posted August 12, 2011 Share Posted August 12, 2011 The unit picks up its ground from the housing mechanism being screwed down to the tank AND through the retaining ring making contact with the tank and the housing.It is important to clean all the surfaces with a wire brush/scouring pad before reinstalling so as to get a good ground.Keep us posted as to what happens next.Joe Link to comment Share on other sites More sharing options...
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