jframe Posted April 5, 2018 Share Posted April 5, 2018 Finally put the 65 in a shop that works on a lot of older vehicles, and let them check my fuel gauge issue. They are CONVINCED it is the gauge. I took them a used gauge I had, and was told it wasn't any better than the one in the car. Does anybody out there have a KNOWN GOOD fuel gauge for a 65 Riviera they would part with? They pulled the gas tank and cluster, and checked everything in between. They said the printed circuit, wiring, and new sending unit I put in were all good, with the sender reading 86 ohms at the full mark and .3 at empty. So I need to get a WORKING fuel gauge, if anyone has one, please let me know. Link to comment Share on other sites More sharing options...
Seafoam65 Posted April 5, 2018 Share Posted April 5, 2018 The fuel gauge in my Dad's 65 Riviera went bad in 1968 and we had to replace it. There was an nos one on ebay for a reasonable price about a year ago, and I pointed this out and a couple of people on the forum said no need to buy it, that used ones are plentiful. I guess now we will see if that is the case. I should have bought it myself because I knew that they go bad because my Dad's did. Now I wish I had so I could sell it to you. They only wanted 80.00 for it. Link to comment Share on other sites More sharing options...
jframe Posted April 6, 2018 Author Share Posted April 6, 2018 1 hour ago, Seafoam65 said: The fuel gauge in my Dad's 65 Riviera went bad in 1968 and we had to replace it. There was an nos one on ebay for a reasonable price about a year ago, and I pointed this out and a couple of people on the forum said no need to buy it, that used ones are plentiful. I guess now we will see if that is the case. I should have bought it myself because I knew that they go bad because my Dad's did. Now I wish I had so I could sell it to you. They only wanted 80.00 for it. I know, I saw it too. These guys ohm'd everything right up to the cluster and said wiring, print circuit, sender, everything did good but the gauge. An NOS one sure would be nice. They put in the used one I had in a box, and it does somewhat better, but didn't go past 3/4 full when I filled up. Link to comment Share on other sites More sharing options...
pyntre Posted April 6, 2018 Share Posted April 6, 2018 I literally threw my old one out 3 weeks ago ,,, going through all my left over parts ,,, for some reason it had the most noxious smell you could ever imagine coming from it ,,, don’t know what chemical or compound that was from in it but it was stinking up the whole box of parts ,,, not that that helps you ,,, gotta be one floating around ?? 1 Link to comment Share on other sites More sharing options...
jframe Posted April 6, 2018 Author Share Posted April 6, 2018 MAY have one located on Fleabay; the used one that I had is in it now, and it works SOMEWHAT better than the original. Link to comment Share on other sites More sharing options...
pyntre Posted April 6, 2018 Share Posted April 6, 2018 And that’s not what I would call an easy part to swap out ...yikes !!! Link to comment Share on other sites More sharing options...
jframe Posted April 6, 2018 Author Share Posted April 6, 2018 3 hours ago, pyntre said: And that’s not what I would call an easy part to swap out ...yikes !!! It's no problem. Take an Allen wrench to the set screw in the chrome bezel in the cluster. Pop it off along with the black shield containing the warning light screens, and it's 3 screws to get the gauge out. Easy peasy. Link to comment Share on other sites More sharing options...
pyntre Posted April 6, 2018 Share Posted April 6, 2018 Well that works !!! ?? that’s probably the easiest thing to do on the whole car ,,,, darn it’s a complicated beast sometimes !!!! Link to comment Share on other sites More sharing options...
jframe Posted April 7, 2018 Author Share Posted April 7, 2018 18 hours ago, pyntre said: Well that works !!! ?? that’s probably the easiest thing to do on the whole car ,,,, darn it’s a complicated beast sometimes !!!! It sure is. Been chasing this problem since I bought it 2 years ago. Link to comment Share on other sites More sharing options...
CTX-SLPR Posted April 7, 2018 Share Posted April 7, 2018 '65's have reversed Ohm range from the earlier cars don't they? Link to comment Share on other sites More sharing options...
Bloo Posted April 7, 2018 Share Posted April 7, 2018 (edited) I do not believe so. GM cars used 0-30 ohms from the 1930s until about 1964(?), and then switched to 0-90 ohms, which they kept until 1996 or so. 0 ohms is empty. The design is ridiculous, because any stray resistance will cause the gauge never to get to empty, likely leaving the owner stranded. 0.3 for empty is perfect. It is hard to get a sending unit to go that low, even though it needs to. 86 is still 4.3 ohms short of full. That doesn't sound like enough to cause you to top out at 3/4, but maybe. If you have an electronic supply locally, I would grab some resistors that add up to exactly 90 ohms, substitute them for the sending unit, and see what happens. It is a "balanced coil" type gauge, and you can read about that online. Most pages are about British cars. Resistances will be different, but the principle will be the same. You may be able to figure out how to calibrate the gauge that gets to 3/4, (assuming it still only went to 3/4 with 90 ohms connected). Edit: disconnecting the wire should cause the gauge to peg full. Does it? I don't remember. If it wont go high with the wire disconnected, disregard that last paragraph. Edited April 7, 2018 by Bloo (see edit history) Link to comment Share on other sites More sharing options...
RivNut Posted April 7, 2018 Share Posted April 7, 2018 63 and 64s use 45 ohm gauges. Link to comment Share on other sites More sharing options...
jframe Posted April 7, 2018 Author Share Posted April 7, 2018 Yes, mine is a 90 ohm unit. And when you unplug the wire it pegs full. Link to comment Share on other sites More sharing options...
jframe Posted April 7, 2018 Author Share Posted April 7, 2018 I am still thinking it's a gauge issue, because the original reads at a different point when full vs this used gauge that is in it now. Plus, the gauge in it now swept from near empty over to the 3/4 mark when I filled it in a big hurry vs the original taking FOREVER. Link to comment Share on other sites More sharing options...
RivNut Posted April 7, 2018 Share Posted April 7, 2018 Sounds to me that if the gauge will peg, it's not the gauge. I'd be looking at the sending unit. The reostat on the sending unit will get a build up of shellac on it and you can't get a reading through the shelac. Link to comment Share on other sites More sharing options...
Bloo Posted April 8, 2018 Share Posted April 8, 2018 That may be, but at 0.3 ohms he has less shellac than most of us at the low end, At the high end, the shellac would help. I'm not really disagreeing with you though, I also suspect the sending unit. 90 ohms worth of resistors would put it to bed in a hurry. That should make it read "full". If not, its the gauge. Maybe the float arm is bent a little. Typically a GM gauge has little room for error. If the float touches the bottom, it never gets to zero. 0.3 ohms is about the best zero I have ever seen. Maybe the float is hitting the top of the tank before it gets to 90 ohms? 1 Link to comment Share on other sites More sharing options...
fatbuick Posted January 31, 2020 Share Posted January 31, 2020 So, can anyone confirm how many ohms a 65 Riv has? is it 0-90 ? Link to comment Share on other sites More sharing options...
1965rivgs Posted January 31, 2020 Share Posted January 31, 2020 41 minutes ago, fatbuick said: So, can anyone confirm how many ohms a 65 Riv has? is it 0-90 ? Yes Tom Link to comment Share on other sites More sharing options...
fatbuick Posted January 31, 2020 Share Posted January 31, 2020 Thanks very much Tom Link to comment Share on other sites More sharing options...
jframe Posted January 31, 2020 Author Share Posted January 31, 2020 As a long overdue update, I pulled the tank and sender again, and actually bent the arm of the sending unit just slightly, and now it goes much closer to "F" when it is filled up. 1 Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now