DE 13.5 inch Fuel sending unit for 23 gallon rear tanks - New option

[mp]

MP I will send you pm.

Funds in mail for two each. Thanks.

 

[hyghlndr]

Senders just arrived!

Can the following please pm me shipping address:
John Hoover
guy giuffre
Steven Benefield


MP received the check.

Thanks all.

 

[rbrodder]

23 gal sending unit

Are there any of the
se still available? Thanks

 

[hyghlndr]

TTT. Can the following please pm me shipping address:

Steven Benefield

 

[blksn8k]

Got mine today. Install was simple since my tank has the same bolt pattern as the new sending unit but I did use the old screws since the new ones were apparently metric thread.

Unfortunately, this new sending unit is even less accurate than the one that came with my old BC tank.

My tank currently has about 10.5 gallons in it and when I bought it in 2004 it was rated at 24 gallons. That works out to about halfway between 3/8 and 1/2 full (7/16).

The old sending unit was reading 33.7 Ohms at this fuel level which translated to about 1/8 tank on the Autometer gauge which is rated for 73-10 Ohms.

The new sending unit reads 53.1 Ohms at the same fuel level which translates to "E" on the gauge.

Either sending unit would need to register about 28 Ohms of resistance at the current fuel level for the gauge to read accurately between 3/8 - 1/2 full.

The top of the composite float on the new unit rides even with the top of the fuel in the tank which right now measures exactly 6". With the sending unit wired but out of the tank it reads 53.1 Ohms with the top of the float at 5.5" from the bottom of the vertical shaft. My tank is 14" deep from the top of the sending unit mounting flange to the bottom of the tank and the sending unit is 13.5" from the underside of the flange to the bottom end of the shaft. 5.5" + .5" = 6" which shows that the float is completely submerged in the fuel vs floating on top. Not saying that is wrong - that's just how it works. But if it did float on top it would be more accurate. Just sayin'.

Anyway, the new sending unit reads 73.4 Ohms empty and 10.7 Ohms full. On the Autometer gauge that translates to about 1/8 tank below "E" and 1/8 tank above "F".

I will say that this new unit appears to be well made and should be more reliable than the old swing arm thing that the tank came with which quite honestly didn't even work until I took it apart and fixed it. I just wish this new design was more accurate.

At this point I still have over ten gallons of reserve when the gauge reads "E". If I fill it up every time it gets to E I might as well have kept the stock tank.

My next step will be to talk to Autometer to see if their Fuel Signal Adapter, which mounts between the sending unit and the gauge, is capable of correcting, or at least bettering, my situation.

 

[blksn8k]

Update: I purchased the fuel signal adapter module from Autometer and installed that today.

https://www.amazon.com/gp/product/B085D76YX6/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

By using the "Learning" mode on the module I have been able to get the gauge to read much more accurately. With about 10.5 gal in the tank it is now reading slightly above 1/4 tank. That's still not exactly right (should be closer to about 7/16 tank) but it's way better than "E" which is what the gauge was reading with the same amount of fuel but without the module. As I drive it and see how it reacts to different fuel levels in the tank I should be able to tweak it a little more but this is good enough for a starting point.

I also made my life way easier by cutting an access opening in the floor so I can get to the sending unit without dropping the tank. You can see what that looks like in the photo I added in one of my previous posts in this same thread.

That made making adjustments on the module so much easier because you absolutely need to have access to the sending unit in order to make those adjustments. You could still do that without the access opening but you have to do it with the sending unit out of tank which means without the opening you would have to do all that before you install the tank. If I need to make any future adjustments to the gauge all I need to do is remove six screws and pop the "door" off.

Here's my crazy theory on why this new sending unit is so inaccurate at the lower fuel levels:

The gauge is nothing more than an Ohm meter. In other words, it measures resistance to electrical current. As the fuel level drops so does the float. Since the sending unit shaft is a solid metal (stainless steel) rod there is more resistance in that rod the closer the float gets to the bottom of the rod because the electrical current is effectively having to pass through more of the rod.

The higher the amount of resistance (Ohms), the lower the gauge reads. It's not supposed to read "E" until it sees 73 Ohms but in my case the gauge was reading "E" at 53.1 Ohms or 6" from the bottom.

My theory is that if the rod were tapered so that it was a smaller diameter at the bottom than it is at the top, there would be less resistance in the rod than there is now as the float gets closer to the bottom which would allow the gauge to read higher than it did without the module. I have no idea how to calculate the amount of taper required but knowing that it requires a measured 24 Ohms for the gauge to read accurately with the amount of fuel currently in the tank (10.5 gal) should be a starting point.

There obviously also has to be enough resistance in the shaft when the float is at the bottom of the shaft so that the gauge will still read "E" when the tank is empty and that would limit how small the diameter of the rod can be at the bottom.

Another, and perhaps easier, way to do the same thing might be to drill a hole in the bottom of the shaft or even a series of small holes through the shaft. However you do it the goal would be to remove just enough mass but not too much.

The bottom line is it needs to read "E" when the tank is closer to empty, not when it is nearly half full. And if the sending unit were more accurate you could eliminate the need for a signal adapter module.

 

[hyghlndr]

For anyone with a stock guage please see my other post on the shorter ones to set to full when you have a full tank. I did this on two, the others didn't need it. Remember the factory gauges are 40+ plus years old.

Check your ground- should be screwed to perfectly clean metal.

Here is testing, about 73 empty, 40-43 halfway and about 11 full. Also show about 1/4 and 3/4 full. Seems pretty much where things should be.

 

[BradinEDH]

I installed the new sender in my 23 gallon Sherman tank Older style. Filled it up and the gauge read up past full. Drove 100 miles and it went down to just off of E. I filled it back up to see what was really in there and it topped off at 13 gallons. So I think there was about 10 gallons left at E. How do I calibrate the gauge so Empty is much closer to E. I am good with 2-3 gallons left but not 10. When I initially filled the tank it seemed to move the needle after 3 gallons were added 1 gallon at a time. But not now??

Brad

 

[hyghlndr]

Please see my other ad for fuel senders detailing how to set your factory gauge. You do not have to take it all apart as seen in the one reference document. I would also make sure you have nice clean smooth metal for ground by tank, and your voltage regulator by cluster is working properly.

 

[77broncotx]

My rear tank is 13" deep. A previous owner installed a tank that is for sure deeper than the 23 gallon. I'd love to buy a sending unit like you offer and I'd consider using the 23 gallon unit if you don't have anything else. Let me know what you have that might work how to order. Thanks.

 

[hyghlndr]

These senders are 13.5 inches long, that is about as deep as I have seen. Maybe measure your's to double check length. I only have 3 left.

 

[77broncotx]

I can use the shorter one for the 23 gallon and consider there being a reserve. How do I order?

 

[hyghlndr]

Just send me a PM message. I didn't see that you had it enabled for me to send.

 

[77broncotx]

I can't find the link for a PM. Nothing I am familiar with works. Sorry. Please send how to order info to dusty.farrell@gmail.com