Fuel tank sending unit

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76Scamp

76Scamp

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I thought I would share an experience I have had. Searching the forum endlessly for what brand or where I can purchase a sending unit that will make my fuel gauge read correctly, I stumbled upon a posting from Slant Six Dan where he linked to Plum Krazy Garage in Australia because they not only sell a repair kit, but a whole sender. Someone commented on it saying it only works for Stewart Warner gauges. Well, I purchased one anyway. After two weeks of waiting, it is the correct sender for these cars. I put it in my 74 Dart Sport and empty is now empty and not empty is still half tank. It is also non-linear, so everything is correct. It was about $150 and a two week wait, but I feel it was worth it being mine is a daily driver that sees 100 miles a day.

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Huh, I just went to the Plum Krazy site, and the unit they are selling with that part number looks exactly like the one everyone else is selling, with the little short arm and the pivot point halfway down the tube. Image here:
Screen Shot 2024-03-26 at 6.00.19 PM.png

The factory A-body unit had the pivot point up near the exit pipe, with a very long arm, similar to this photo (but this one isn't correct, either, because the sock is straight out instead of at a right angle).
Screen Shot 2024-03-26 at 6.00.53 PM.png

Keep looking...
 
I knew I had this photo somewhere.... bottom item (shiny) is a new sender from Jeg's or Summit (I forget) — exactly the same as the PlumKrazy part above (and much cheaper). Top is the factory A-body sender — completely different.

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76Scamp said:
My car has the original cluster that every American made A body came with.
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Ummm just to clear this up, "EVERY American made A body" did NOT come with the same cluster, so I have no clue what you're talking about.
 
mvh said:
I knew I had this photo somewhere.... bottom item (shiny) is a new sender from Jeg's or Summit (I forget) — exactly the same as the PlumKrazy part above (and much cheaper). Top is the factory A-body sender — completely different.

View attachment 1716227390
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I've never seen this sender that you are showing as an original type. Only the one with the pivot in the middle. Even original ones I've removed are that middle pivot style. At least on the 74-76 models I've worked on.


Mike69cuda said:
If it really is non linear, then this could be a big improvement.
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I would have to say it is. Using it in my daily with the factory gauge, it's not amazingly accurate, but empty is now pretty close to empty, and a half tank reading takes close to a half tank worth of fuel. Whereas with other senders I've tried across other cars I've owned, every time, empty would actually be half tank. This one is pretty darn close to correct. I'm sure the gauge isn't exactly spot on either, but it's definitely close enough.
RustyRatRod said:
Ummm just to clear this up, "EVERY American made A body" did NOT come with the same cluster, so I have no clue what you're talking about.
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cluster.jpg

Random picture from the internet, but this is the only cluster in the A body that I am aware of from I believe 1970-1976. If there is another, I've never seen one. I've had several 74s, a 75, and 76, and scrounged parts from several in junkyards going back to 72. Swingers, Dusters, Valiants, I've only ever seen this in them. Even in videos and pictures. If there was a different one available, I'm curious as to what it is.
 
76Scamp said:
I've never seen this sender that you are showing as an original type. Only the one with the pivot in the middle. Even original ones I've removed are that middle pivot style. At least on the 74-76 models I've worked on.



I would have to say it is. Using it in my daily with the factory gauge, it's not amazingly accurate, but empty is now pretty close to empty, and a half tank reading takes close to a half tank worth of fuel. Whereas with other senders I've tried across other cars I've owned, every time, empty would actually be half tank. This one is pretty darn close to correct. I'm sure the gauge isn't exactly spot on either, but it's definitely close enough.


View attachment 1716227434
Random picture from the internet, but this is the only cluster in the A body that I am aware of from I believe 1970-1976. If there is another, I've never seen one. I've had several 74s, a 75, and 76, and scrounged parts from several in junkyards going back to 72. Swingers, Dusters, Valiants, I've only ever seen this in them. Even in videos and pictures. If there was a different one available, I'm curious as to what it is.
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You didn't specify a year in the post I replied to. also, there ARE differences between 70-76.
 
All the A-body Plymouths from 70 to 76 look a lot like that - Dodge started using them in 1972
 
The picture in #6 , looks like the orginal senders in my '69 and '72. The older one in the picture, top.
 
IMHO what is important is that you know before you run out of gas. You can hook up the sender before installation and bend the arm to make sure that critical information is available to you. Just how important is it to know when you have exactly half a tank??? I usually bend mine so that when it says E I still have a few gallons in the tank.
 
str12-340 said:
All the A-body Plymouths from 70 to 76 look a lot like that - Dodge started using them in 1972
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Yes the look is very similar, but they differ greatly in some instances. The main cluster connector and the later shunt style amp gauge are but two examples.
 
RustyRatRod said:
You didn't specify a year in the post I replied to. also, there ARE differences between 70-76.
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In the beginning post, I did state this was going in a 1974, so I figured that would carry through the whole conversation about the year range in question.

str12-340 said:
IMHO what is important is that you know before you run out of gas. You can hook up the sender before installation and bend the arm to make sure that critical information is available to you. Just how important is it to know when you have exactly half a tank??? I usually bend mine so that when it says E I still have a few gallons in the tank.
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That is what I have done in the past on other cars where I bought whatever was available as a replacement. I don't care about knowing where half tank is, just that with every sender readily available in the US, they are incorrect and empty means half. As a non linear system, roughly 28ohms would give a half tank reading, but everything other than this isn't set up that way. This sender from Plum Krazy Garage is the first that I've put in that is almost spot on without having to bend the arm.
 
I bought the repair kit (resistor block) from them for Bazza's '71 VG (factory VDO gauges) last summer, and it seemed to work just fine. But I have to admit I never checked it at half-tank.

I have to go up there and reinstall the tank in a few weeks, and this post is making me want to double check all of my work before I call it good.
 
76Scamp said:
every sender readily available in the US, they are incorrect and empty means half.
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I think that this over simplifys the situation. Yes the non-linear thing make the unit less useful. If you connect the unit while out of the tank (connect it to the wire at the tank and ground the unit) you can get someone to sit in the car and you can move the arm to see how it reads on the gauge. By bending the arm you can adjust where it reads. This doesn't fix the arc of the reading but can change what the gauge reads in the the critical area. If you start the process with the amount of gas that you want in the tank when the gauge reads E, then you can adjust it to read that by inserting the unit and holding it in place an then seeing what the gauge reads and adjusting the arm. It might take a few trys to get it where you want it. Yes this really isn't something you can do without a helper, but all that person need to know how to do is read the gauge and yell to you.

By the way, it is my experience that if you have installed a transistorized IVF for your gauges, that the needle moves to much more slowly than the stock IVF and you have to be patient when getting new readings when you move or bend the arm - be patient until the gauge really stops moving.
 
I still have my old IVR, going to switch out the new one and see if that does something. I just replaced it when I needed a new circuit board.
 
The sending units changed over the years.
In part this may have been because the fuel tanks changed.
We also know from Redfish that the gage unit calibration changed - I forget the year. Search will turn it up. Also sometimes the gage itself would be tweaked or the hash marks on the gage placed in the right spots in production.

" In the mid sixties to the early seventies the part number was 2421493.
From around 1973 to 1975 or early 1976 the number was changed to 3621515.
Then Chrysler changed the number to 4051004."
posted here

Part numbers I looked up were:
1967 p/n 2257 493
1973 p/n 3621 615
Which doesn't quite match with the numbers Impreza wrote (but I think he was working from memory)

Mattax said:
The other problem with the replacements is the float arm length.
See Fuel Sending Units and A-Body Fuel Tank Map
also seen in the following thread where
@Cuda Al shows his repair in detail -
Fuel Sender Rebuild
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I wouldn’t think the long arm vs the short arm would be s big deal. The arm can be bent to sweep the same range.

However the non linear winding on the potentiometer that is designed to compensate for the spare tire cutout is a big deal. That can’t be adjusted out by bending the sender arm.
 
Mike69cuda said:
However the non linear winding on the potentiometer that is designed to compensate for the spare tire cutout is a big deal. That can’t be adjusted out by bending the sender arm.
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Technically it can, but the gauge won't read correctly. Bend the arm so that when the tank is almost empty, the gauge indicates empty. It will just stay on full forever, and then start rapidly dropping once the level gets low enough to move the float. It's what I've done in the past so I knew if I had gas or not.
 
76Scamp said:
Random picture from the internet, but this is the only cluster in the A body that I am aware of from I believe 1970-1976. If there is another, I've never seen one. I've had several 74s, a 75, and 76, and scrounged parts from several in junkyards going back to 72. Swingers, Dusters, Valiants, I've only ever seen this in them. Even in videos and pictures. If there was a different one available, I'm curious as to what it is.
Click to expand...


1970-71 Dusters and 1971 Demons had the option for the "Rallye" dash seen in 1967-69 Barracudas. Discontinued for 1972.

Photo is my '72 Duster with a Rallye dash, just because I like it better:

IMG_20231231_185212499.jpg
 
I need one for my 68. My question is why should anyone have to monkey around bending a senders float arm and settling for a gauge that will not function the way it did from the factory and will suddenly drop like a rock and read somewhat correctly again when empty? There is no excuse why any of these companies couldn't have put the care into making a sender that would fit and function correctly for these cars.
I was hoping that these Australian senders would be the answer to this problem and function correctly. The original poster says they do. I sure hope if I shell out nearly $200 for one it will.
Weren't these guages for these Darts made by Stewart Warner for Chrysler? I'm not sure about the 60's but I believe they were in the late 1950's. I remember seeing that somewhere.
 
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I used a Meter Match on mine to calibrate the aftermarket sender to the gauge. Not perfect, but works pretty good.

I also made a calibration box so you can calibrate the Meter Match without adding or removing gas from the tank. It is available for loan.

IMG_0774.jpeg
 
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