fuel sending units , c'mon

[poppa]

Can't I get one that even remotely close?   Wuz up wit dat?? On empty until 3/8 ,and only goes to 7/8 when it should say full. Got 2 from different places ,one has plastic float , one has brass so I'm pretty sure 2 different manufacturers. HELP !!!!!!!    

[Ghoste]

They're all pretty much junk as far as I've been able to find out.  A lot of them claim to calibrate them but they seem to all use the same style of rheostat.

[poppa]

I believe it ohm's out correctly ,10 and 73???

[Pete in NH]

Hi,

At 73 ohms the gauge should read empty and at 10 ohms full. At 24 ohms the gauge should read 1/2 scale. That is where the problem is with  the repop senders. Mid way between 10 and 73 is 41 ohms not the 24 the Chrysler specification calls for. The repop senders are apparently wound in a linear manner not the tapered nonlinear manner of the originals.

This has been an ongoing issue and it's beyond me why the original resistance winding can not be copied. I suspect all the reproduction junk is coming out of China and vendors selling this stuff don't seem to care that what they are selling is incorrect and insist on getting the part made correctly. There was some talk about getting senders made by the original manufacturer but, I don't know what ever came of that.

There is an electronic conversion device that claims to match these poor reproduction senders to the Chrysler system. I don't know anything about them but take a look at http://technoversions.com/MeterMatchHome.html

[poppa]

That (original manufacturer ) fell through. I called early this spring. Probably not enough to make a run. Bummer

[Lennard]

Bring the poor quality under Classic Industries attention? If anyone can persuade a manufacturer to change their ways it's going to be a giant business like them.

[Dodge Don]

http://www.1970chargerregistry.com/mboard/index.php?topic=3537.0

[Lennard]

http://www.1970chargerregistry.com/mboard/index.php?topic=3537.0

Great, thanks for the info!

[maxwellwedge]

I'm still skeptical......a little less......but still. 

I guess I'll try one.

[Ghoste]

Me too, on both points I guess.

[poppa]

I ended up getting 2 ,one from Rock Auto and one from Kramers.I hooked them both up ,outside the tank , Kramers went to 7/8ths so I used that one. Now in the tank it goes to 3/8ths. Go figure. I will pull again and the gauge cluster and try to calibrate one more time.

[el dub]

 how many gallons is a tank supposed to hold?

[myk]

19?

[John_Kunkel]

Whenever I doubt a senders accuracy I use half-watt resistors (75, 25, 10 ohms) between the tank connector and a good ground...this will tell you if the body side of the gauge circuit is accurate.

[poppa]

John , between the connector and a good ground , on the ground side??? Thanks for the help

[John_Kunkel]

Use jumpers to hook one side of the resistor to the wire that goes to the fuel sender and the other side of the resistor to ground. The system uses the metal fuel line as ground but I don't trust that, use a bare steel part of the frame (then check for continuity between the frame and the fuel line).

10 ohms should be full scale on the gauge, 25 ohms about half-tank and 75 ohms empty.

[John L]

I ended up getting 2 ,one from Rock Auto and one from Kramers.I hooked them both up ,outside the tank , Kramers went to 7/8ths so I used that one. Now in the tank it goes to 3/8ths. Go figure. I will pull again and the gauge cluster and try to calibrate one more time.

I also got a sending unit from Kramers after reading how good they were on the 70 registry. I checked it before installation and it worked great and the gage went to full. After buttoning everything up and filling the tank the gage only went to just above half (very frustrating). I have a suspicion that the float does not go all the way to the upper stop tab, but I will not be able to test that out until I run the tank dry again so we will see. I'm going to hit Radio Shack next week and try John's testing method using the resistors.

[charger Downunder]

Went through the 3/4 tank some time back with a new sender. Had to bend the float shaft a pain to do. I had to bend it in a way so it would let the sender unit that is covered up get to the end of its travel plus i bent the stop pin a bit too. Hard to explain you dont bend the end of the shaft where the float is. It has to be bent where it comes out of the sender unit itself. Make sure you bend it the right way. You want to get more upwards travel on the shaft before it hits the stop. So it has to be bent down.

[Ghoste]

Who did you buy it from and does it read correctly in the other parts of its travel now?

[70sixpkrt]

Any updates on this? I need a new sender also.

[Kern Dog]

It almost makes sense to modify an OEM 5/16" sender with 3/8" tubing.  Factory accuracy with improved flow.

[Dino]

It almost makes sense to modify an OEM 5/16" sender with 3/8" tubing.  Factory accuracy with improved flow.

Don't make it too hard.  Buy a new 3/8" sender, remove the resistor box and weld the one from the 5/8" sender in its place.  Cut both ground straps, overlap them and weld them together.  Problem solved.  Been running mine like that since last year and the fuel gauge is spot on.  It's on my bench waiting for the new tank so I can get some pics tomorrow if you want.

[Ghoste]

Provided you have an old one.

[Lennard]

I think it's ridicules that after you've spend over $100 for the #@*°  thing, you have to take it apart/modify/rebuild it to make it function properly!

[66FBCharger]

Don't the new sending units available from Kramer's solve the problem?

[Ghoste]

No one seems to know for sure.

[70sixpkrt]

I ordered one from Kramer. They check the calibration before they shipped it out. Some people have no problems and some do with there units.

[Ghoste]

Let us know how you make out with it.

[70sixpkrt]

I won't be able to install it for about another month.

[Lennard]

Don't the new sending units available from Kramer's solve the problem?

See John L´s reply in this topic.

[poppa]

mine didn't....yet

[70sixpkrt]

Well I just installed the sending unit and, wait for it, it reads FULL.  

[Lennard]

Well I just installed the sending unit and, wait for it, it reads FULL.  

With an empty fuel tank? 

[70sixpkrt]

With almost 3 gallons in it, it read empty. Put 16.10 gallons and it read full.

[Lennard]

Great, thanks for the review. I'll by a Kramer when I get to that point.

[BananaDan]

Hey all, just found this thread. My Kramer's sender is still fine, it's been in the car for almost a year. I just filled the car up yesterday and it went up to full.

[Brock Lee]

Anyone try one of the Spectra "premium" sending units? I put one in, but haven't finished the car up yet. I needed a new unit anyway, so I threw the extra couple bucks hoping it would be at least a little more accurate. The claim is it reads 80-10 ohms.

[Ghoste]

I could be wrong but my understanding is that its less a case of the range it reads than it is how the range is calibrated from one extreme to the other.  The oem ones travel from one point to the other would be a curve if you could see the electrical signal and the repros travel in a linear fashion.  If that makes sense.  Or if my understanding is even correct for that matter.

[Dino]

I think you have it right.   

The original senders would have a resistance of roughly 24 ohm with the needle on the halfway mark whereas the new units are more in the 40 range.  So the gauge will read correct when at empty or full, but not inbetween.

[Brock Lee]

I totally get what you are saying.

In other variable resistors, the resistance from point A to B can be equal, but the taper from A to B can be different. Most commonly used tapers are linear and log tapers.

My guess is the originals were a log taper whereas new ones are  linear taper. A linear taper variable resistors resistance is proportional to where the contacts are located on the strip. Log tapers are very offset. The factory probably chose the offset taper to accommodate the angled bottom of the tank. It takes less fuel to move the float in that area than above the angled portion.

[Ghoste]

So why is it so impossible for them to use a log taper today?

[Pete in NH]

I totally get what you are saying.

In other variable resistors, the resistance from point A to B can be equal, but the taper from A to B can be different. Most commonly used tapers are linear and log tapers.

My guess is the originals were a log taper whereas new ones are  linear taper. A linear taper variable resistors resistance is proportional to where the contacts are located on the strip. Log tapers are very offset. The factory probably chose the offset taper to accommodate the angled bottom of the tank. It takes less fuel to move the float in that area than above the angled portion.

The originals were log taper and there is no reason reproduction units can not be made the same way. It is slightly easier to wind the resistance wire on in a linear manner but, with the right cam on the winding machine a log taper can be done in a very repeatable manner.

I can only think its a combination of laziness, indifference and ignorance on the part of the company's reproducing these parts. It's not like this is an unknown issue and you would think by now it would have been corrected.

[Ghoste]

I just don't get it.

[Brock Lee]

Is whomever that is ordering these specifying log taper? It may just be a case where the manufacturer is making what is ordered. That is something that should be easily available for the asking. The only issue I can think of is the manufacture is currently using a linear taper on other products, so a log taper would be outside their production norm. It still should be doable even for an upcharge. But I still wonder if they even were asked for such a detail. Most likely they are just given a modern sending unit to knock off with the old resistance readings as a spec and that is it.

Anyone figure out if the originals were regular log, or reverse log tapers?

[Mike DC]

 
I recall hearing years ago that the Mopar repro sending units were getting GM-style internal components.  I don't know if that is true or not. 

[Brock Lee]

Could be. I would not be surprised to learn GM used linear taper. Every GM I have ever owned had a gas gauge that moved faster through one half than the other. GM may have set the standard in reproductions, and the companies making them may not even know better.

Anyone know who made the originals? Bendix? Federal Mogul? Briggs and Stratton?

[Ghoste]

Not sure but we did have one member here who approached the oem supplier about getting repros made by them and I think A) he didn't get a lot of response from potential buyers (the deal as I understand it kind of necessitated paying up front but I think with the current state of repro fuel senders everyone now has a wait and see approach) which led to B) the oem supplier wasn't all that interested in such an insignificantly tiny market.

[Lennard]

Not sure but we did have one member here who approached the oem supplier about getting repros made by them and I think A) he didn't get a lot of response from potential buyers (the deal as I understand it kind of necessitated paying up front but I think with the current state of repro fuel senders everyone now has a wait and see approach) which led to B) the oem supplier wasn't all that interested in such an insignificantly tiny market.

http://www.dodgecharger.com/forum/index.php/topic,108809.0.html

[Brock Lee]

Not sure but we did have one member here who approached the oem supplier about getting repros made by them and I think A) he didn't get a lot of response from potential buyers (the deal as I understand it kind of necessitated paying up front but I think with the current state of repro fuel senders everyone now has a wait and see approach) which led to B) the oem supplier wasn't all that interested in such an insignificantly tiny market.

Yeah, I would expect an OEM to want to make and sell a minimum quantity of units. That is the nature of the beast. They are used to making runs of thousands of units at a time, being paid at once. No time to mess around with a small batch and then have to trickle income in..It isn't worth the time. You have to find someone willing to put up the cash and be willing to take a long ass time to recoup their investment and start to make a profit.

If the new Spectras read empty and (at least close to) full, I am happy. I will get used to the in between swing.

[Mike DC]

  
This is stupid.  Why doesn't some repro parts company just get a correct batch made?  Word would get around fast if somebody had the correct ones in stock.  We shouldn't have to be doing it this way ourselves.  

[Lennard]

 
This is stupid.  Why doesn't some repro parts company just get a correct batch made?  Word would get around fast if somebody had the correct ones in stock.  We shouldn't have to be doing it this way ourselves.  

Agreed, see my first post on page one.

[el dub]

If they don't work, send them back. That way you get your money back and the vendor has to go to the manufacture, to get his money back, and the manufacture may start building the correct sender

edit: probably like me, bought it a long time ago and threw away the receipt  

[Ghoste]

I agree 100%.  It isn't a cheap part and it isn't an unknown problem either and yet for some reason they insist on giving us compromised ones and we keep accepting them.

[cavemanno1]

Well I just installed the sending unit and, wait for it, it reads FULL.  

Could you get me the link for it,i might need one!

Thanks

[Lennard]

I agree 100%.  It isn't a cheap part and it isn't an unknown problem either and yet for some reason they insist on giving us compromised ones and we keep accepting them.

I just sent Ray from Classic Industries a p.m. about it.  Lets see if he responds...

[Lennard]

Well, superfast response:

"Lennard,

Thank you for bringing this to our attention. We were not aware of any issue with the fuel senders we offer for Mopar. I will open a case with our quality control / R&D Department and have them look into the matter. In the meantime, if any forum members could provide a lead as to who the OEM manufacturer was, we could possibly open dialog with them to see what it would take to have a run produced.

Thanks again for bringing this to our attention. If you have any additional details you could share, images, etc. regarding which senders this issue applies to, what the original sender windings look like, etc. It would help give the R&D team a head start to diagnose the issue, and come up with a solution.

Best regards,

Ray Yager
Merchandising Director
Classic Industries"

So if anyone can steer him in the right direction, please do so as I don't know anything technical about these things. You can send him a p.m. or email him at ryager@classicindustries.com

[Pete in NH]

I sent Ray an email outlining the basic problem. Lets see what he comes back with.

[Lennard]

I sent Ray an email outlining the basic problem. Lets see what he comes back with.

Perfect, thanks

[ray230]

Hi,

At 73 ohms the gauge should read empty and at 10 ohms full. At 24 ohms the gauge should read 1/2 scale. That is where the problem is with  the repop senders. Mid way between 10 and 73 is 41 ohms not the 24 the Chrysler specification calls for. The repop senders are apparently wound in a linear manner not the tapered nonlinear manner of the originals.

This has been an ongoing issue and it's beyond me why the original resistance winding can not be copied. I suspect all the reproduction junk is coming out of China and vendors selling this stuff don't seem to care that what they are selling is incorrect and insist on getting the part made correctly. There was some talk about getting senders made by the original manufacturer but, I don't know what ever came of that.

There is an electronic conversion device that claims to match these poor reproduction senders to the Chrysler system. I don't know anything about them but take a look at http://technoversions.com/MeterMatchHome.html

Pete, after reading your post I ordered the Meter Match. I had replaced the tank and had a new 1/2" pickup that wasn't reading right. I had to adapt the installation due to short studs on the stock fuel gauge, but was able to install. The product works as advertized. Problem solved!  Thanks for the tip.

[Ghoste]

First grilles for 69's and now possibly this?  Kudos to CI.

[70sixpkrt]

Quote from: 70sixpkrt on August 01, 2015, 12:44:37 AM
Well I just installed the sending unit and, wait for it, it reads FULL.   icon_smile_big icon_smile_big


Could you get me the link for it,i might need one!

Thanks

http://www.kramerauto.com/proddetail.asp?prod=B14-FL-004

[cdr]

I just installed an old original sender & now my gauge reads correct,, also the aftermarket sender lock ring does not hold very tight, it is cheesy. also where the wire connection goes through to the stud end connection for push on wire connector swells up & the seal splits & can leak fuel.

[66FBCharger]

I sent Ray an email outlining the basic problem. Lets see what he comes back with.

I know this is an old post.
Did anyone ever hear back from Classic Industries?

[rollo1504]

 

[Pete in NH]

I did hear back from Ray at Classic Industries. He sent me two sending units and I checked them electrically to the original Chrysler specification. These were both A body sending units. One was right electrically but so poorly made I would never put it in a fuel tank. The second unit was better made but wrong electrically. I wrote up a report and sent it to Ray. His response was that they had so much trouble over these sending units that Classic might stop selling them. That was the last I ever heard about it.

[66FBCharger]

Ugh! This is a part needed by many Mopar people. I don't understand why someone won't step up to build correct working sending units.