Close as you will come to getting an OEM fuel sender..

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Thanks for the tip. Interesting a truck application works better in an A body than a A body one does.
 
toolmanmike said:
What mods did you have to make?
Click to expand...

I have a custom made calibration module similar to the MeterMatch that I and with the help of a couple of my Ham radio buddies designed and built.
I (we) have spent the last 5 years off and on(more off then on)working on this project.
I call my calibration module the G.a.S. Matcher. (Gauge and Sender Matcher).
This module has a total of 11 set points, 9 for fuel level, 1 for a low fuel Alert and 1 for a almost out of fuel alarm.
I may start a limited production soon.
I have two units in use at the present time, one on my "Home-Brewed" car and one on spl440's Dart.
I have also promised two members here modules to test and evaluate and need to get them sent out to these folks.

Herb
 
"Dart67" said:
This is about as close as you will come to getting an OEM fuel sender for your A body.....From personal experience it is close, but still needs a little calibration. Herb https://www.ebay.com/itm/64-70-Dodge-A100-Pickup-Truck-67-70-A108-Dodge-Van-Fuel-Gas-Sending-Unit-5-16/372260478700?ssPageName=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649
Click to expand...

Hello Dart67,
Thanks for the Tip.
Just ordered one.
I have a new tank on the shelf and when it arrives i will bench wire it up with a spare cluster and see how it goes.
When I complete the test run I will post the results on here...
Thanks for the help.
Stay Safe......
Happy Mopar :)
Arron.
 
"Dart67" said:
This unit is the exact physical dimensions as the 1967 - 1969 (that I know of) OEM sender unit and the resistor board is very close as well. Herb
Click to expand...
I recall hearing of this alternate sender many years ago. This guy who had been a service tech at a Dodge dealership said one time it fit and worked fine in the a-body, then in another it hit against the bottom of the tank. He would bend the pickup tube upward a tad so it would mate and seal properly. I have no idea what models those were. I had forgotten all about our discussing this until just now, seeing this thread. At that time the limiter was my problem, not my fuel sender. He told me so much stuff, there's no way I would remember it all. Anyway... this sender at least looks a lot more correct than the one aftermarket lists for a-body. I hope it works for all, no meter match module required.
 
"Dart67" said:
From personal experience it is close, but still needs a little calibration
Click to expand...
I would assume that the sender is more accurate at the lower ranges, the A100 tank is basically retangular where the dart has the notch on the top for spare tire. (Smaller tank for the first 5 gallons or so)

What did your calibrations show?
 
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Hello All,
Received the sender and did a little unscientific testing.
Here are the results.

Form and fit.
1. Received sender in undamaged cardboard box with sender well packed in pillow type insulation to prevent damage.

2. Mounted the sender in test jig. Confirmed sender mounting flange and strainer tube is level and that the pickup strainer itself is lying on the base of the test jig table. Picture 1.

3. Inspected sending unit and noted the following. One side of U shaped tab that holds the float shaft is bent outward causing the shaft to be on somewhat of an angle. Inspected the wiping arm (sliding contact) and noted that the wiper is in contact with the wire wound resistor board and has significant pressure holding the contact against the board. Picture 2. NOTE: the resister board is tapered like the Mopar style.

4. Wile moving the float arm from empty to full it was noted that the float arm is slightly bent. This and that the shaft is not straight in the housing causes the float to progressively twist as the arm goes through its travel. Picture 1 and Picture 3.

5. The travel of the arm is limited to down 28.5° at empty and up 27.3° at full from the center of its travel at 0°. This travel is preset from the OEM using the pre-bent limitation tabs. Picture 4.

6. The following OHM readings were noted.
Empty 28.5° = 80.7 ohm
14.2° up = 61.8 ohm
0° = 36.4 ohm
13.6° up = 21.0 ohm
Full 27.6° up = 10.1 ohm

7. Installed sender into new tank on bench to confirm form and fit. Picture 5.

8. The sender fit well in the mounting hole. The supplied gasket and locking ring also fit well with no exceptions noted.

9. The fuel pickup sat slightly into the recess in the tank just behind the strengthening rib in the bottom of the tank. The float sat just above the rib a proximity 1/4 of an inch.

Notes: When the arm was at the empty position it was not supported as depicted in picture 5 for the OHM readings of ¼ , ½, ¾ and full. Wile obtaining the ohm readings only the multi meter was connected to the sender.

I started to connect up a test cluster to the tank and hopefully will be able to do some more testing but I will first need to calibrate a Fuel Gage using some resisters and a potentiometer. Picture 6.

Hope any of this helps,
Stay Safe.....
Happy Mopar :)
Arron.

Form and Fit pix 1.jpg
Form and Fit pix 2.jpg
Form and Fit pix 3.jpg
Form and Fit pix 4.jpg
Form and Fit pix 5.jpg

Form and Fit pix 6.jpg
 
Some of what you found could be quality control related. We never know if a previous buyer has handled an item then returned it to the seller.
The traveling contact, be it brass or copper, is the softer metal. It will wear away before wearing through the resistor wire. Its size puts 2 or more laps of wire under it in any position. Higher pressure = faster wear. It needs only to lightly touch to complete the circuit.
I certainly wouldn't be happy with it as received/shown in your 2nd pic. I dont know if I would attempt to fine tune its mechanical form, or return it for exchange.
One of your measurements is 0 degrees equals 36.4 ohms. I know that resistance should be close to 1/4 tank. So if 0 degrees is presumed 1/2 tank, where is the fault? Picture suggests your fixture holds the sender at plumb. It is not plumb when mounted in the tank wall. Even the vehicles stance has a bearing on that walls angle. Consider the shape of the tank and it gets quite complicated. "did a little unscientific testing" is all any of us do.
You can calibrate your gauge to that OEM limiter power supply. The multitude of owner using alternative power supply such as the 7805 solid state regulator would see slightly lower needle positions from same resistance values.
At the root of it all... we are dealing with 40+ year old technology, very basic thermal range indicators for gauges. We don't know how much exactness the factories engineers put into these senders. Those owners who put too much trust in the things back in the day would learn their lesson once stopped on the shoulder, out of gas.
I probably will try one of these senders next time I need one. Meanwhile I just be glad that gas prices are down, pumps are on every corner (that wasn't so back in the day) , and keep plenty in it.
 
@rich006 tested an earlier original sender, that seems to be the type use in the 60s.
But I *think* the fuel level was estimated from angle, not measured direct. Maybe he'll chime in and clarify. Anyway it looks similar to Dana's findings but shows the longer arm covers the full range better.

orx3fpj-png.png


he was the thread starter Fuel Gauge Sending Units compared
 
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toolmanmike said:
Will higher resistance read lower on the gauge? (looking at the Spectra sender at about 3 gallons)
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Yes. The needle rotates as more current heats the bimetal. Redfish has explained this well.. somewhere..in some post.
 
Mattax said:
Yes. The needle rotates as more current heats the bimetal. Redfish has explained this well.. somewhere..in some post.
Click to expand...
I have read some horror stories about aftermarket senders. I can put up with some inaccuracy as long as the gauge reads close when it gets to empty. In a perfect world the gauge would read E with a gallon or so left in the tank.
 
toolmanmike said:
I have read some horror stories about aftermarket senders. I can put up with some inaccuracy as long as the gauge reads close when it gets to empty. In a perfect world the gauge would read E with a gallon or so left in the tank.
Click to expand...
If it was just 1 gallon, I could live with that.
I suppose for some folks an advantage of a short arm is that they can show empty while there's still 2 to 4 gallons remaining.
I'd prefer the thing more accurate and not having to wonder if 1/2 on the gage means 8 gallons or 5, and especially what 1/4 means.
 
Mattax said:
If it was just 1 gallon, I could live with that.
I suppose for some folks an advantage of a short arm is that they can show empty while there's still 2 to 4 gallons remaining.
I'd prefer the thing more accurate and not having to wonder if 1/2 on the gage means 8 gallons or 5, and especially what 1/4 means.
Click to expand...
True that. All in getting used to the new sender. Run it to 1/2 on the gauge and fill it up just to see.
 
Dart67, thank you for all of the time & research you have put into the fuel sending unit setup. I wish my buddy & I had found this earlier to save us all of the headaches we encountered with the "Chinesium" sending units. We have now acquired am OEM sender & will be sending it off to Wolf & Co. for a rebuild.
 
@Aaron Tate, that is awesome!

Something to remember is the tank is not rectangular, it has a taper on the bottom and the spare tire recess on the top.

All this means is the angle of the float arm will not be equal to the guage reading per gallon. The float will lower faster in the full to 3/4 range (till it gets under the spare tire indent), then approximately a constant rate from there till empty.

Your plan to use a guage is spot on.

Great work
 
Hello All,

To answer some of the questions posted i offer the following.

The picture of the sender installed into the tank was taken with my I Phone wile the tank was on the bench looking through the filler neck hole.

The testing so far was done with the "Q/C / possible damage" issues in tact to represent what someone could expect when buying this product. As Dart 67 originally stated (and I totally agree with him) Quote "But still needs a little calibration".
I only bought the sender to play with on the bench and see if it was any good. No intentions of sending it back other then probably in the recycling bin although I may correct the issues and re-test it just for fun and then send it to the recycling bin.
The testing was done in the jig at plumb so there would be a constant in case I wanted to do any other testing at a later date and or compare this sender to another manufactures sender and or it would limit the unknown / uncontrollable variables that would be encountered wile installed in the tank / car. That part of the test will be done with the tank on the bench and wired up to the cluster.
The fault noted at 0 degrees could be numerous. Resistor board design, placement of board in relation to arm travel, wound wire incorrectly spaced and so on. The other issue is that if the original design was 10 to 70 Ohm throughout the arms sweep it was noted that the Ohm reading was 80.7 Ohm and not 70.0 Ohm at full travel down (E). Possibly may only need to adjust the stop for empty ?
I was planing to "calibrate' the gauge with a combination of three things to see if there is any notable differences. OEM style IVL, Solid State IVL, and my trusty Siglent SPD3303X-E in conjunction with three known value resisters providing the load on the gauge.
Will keep you updated when test two is finished.
Thanks in advance,
Stay Safe.....
Happy Mopar :)
Arron.
 
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Watch the sock to tube connection on these aftermarket senders. In 8 years mine was completely loose. And I noticed a brand new one had glue on the connection. Can’t remember if mine did originally.

The sock connection is stepped inside. It fits 5/16 and 1/2”. Not sure if the OE sock is like that.

Recently I had some rubber flake debris in the carb and filter. It would clog the float. I’d blow it out and then car would run fine until it did it again. I narrowed down to my sending unit rubber line (8 yrs old).

When I pulled sending unit to check things there wasn’t a sock on it. I have a wireless Depstech brand mini probe camera. I snaked it down the filler tube and I saw the sock was loose in the tank.

After an intense 2-man game of “Operation” we fished it out.

The sock fit so loose if you tilted the sending unit downward, the sock would slide off.

We put a little nipple flare in the end of the pickup tube and its tight and snaps on.

First pic is unit “as found” without the flare on end of tube. I also had the ‘71 style vent nipple finally welded shut.

DFEBCEE6-2970-4DAC-BA08-9ECC83C0AA0A.jpeg


7A37CB9C-5DCF-484A-8D6A-4086131A3A50.jpeg
 
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Arron tate said:
The other issue is that if the original design was 10 to 70 Ohm throughout the arms sweep it was noted that the Ohm reading was 80.7 Ohm and not 70.0 Ohm at full travel down (E). Possibly may only need to adjust the stop for empty ?
Click to expand...
The full tank resistance is closer to 74 Ohms. So 80 isn't awful.
Maybe it also matches the later fuel gages @RedFish mentions in this post: Gauge Cluster Issues/IVR

@toolmanmike This shows the internals and more
Thermal-Electric Gauges (Session 227) from the Master Technician's Service Conference
 
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autoxcuda said:
Watch the sock to tube connection on these aftermarket senders. In 8 years mine was completely loose. And I noticed a brand new one had glue on the connection. Can’t remember if mine did originally.

The sock connection is stepped inside. It fits 5/16 and 1/2”. Not sure if the OE sock is like that.

Recently I had some rubber flake debris in the carb and filter. It would clog the float. I’d blow it out and then car would run fine until it did it again. I narrowed down to my sending unit rubber line (8 yrs old).

When I pulled sending unit to check things there wasn’t a sock on it. I have a wireless Depstech brand mini probe camera. I snaked it down the filler tube and I saw the sock was loose in the tank.

After an intense 2-man game of “Operation” we fished it out.

The sock fit so loose if you tilted the sending unit downward, the sock would slide off.

We put a little nipple flare in the end of the pickup tube and its tight and snaps on.

First pic is unit “as found” without the flare on end of tube. I also had the ‘71 style vent nipple finally welded shut.

View attachment 1715537825

View attachment 1715537826
Click to expand...

Definately at least two types of sock filters. One is cylindrical the full length and the other is flat on the closed end. I was concerned with the flat type collapsing. I had that happen with a brass filter in a Tacumsa gravity fed tank. That surprised me.
 
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