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Help with fuel cell sender unit
Posted: Mon Jan 23, 17 3:44 pm
by Aitch
Help needed, I've got Terry's old Demon and have a foam filled fuel cell in the boot which as far as I can tell is a 10 gallon unit. My problem is the fuel gauge has just stopped reading anything but half full. Now I assume it's the sender unit but I don't know if it's a tube with float style unit or a pivoted arm sender unit, again I assume it's a tube with float style as its a foam filled tank. Can anyone get hold of Terry so I can find out who made the tank and if I can get a new sender unit etc as everything on the car is of unknown origin so it makes it difficult to source parts or who to talk to for help. I don't really want to buy a new fuel cell for the sake of a sender unit if one can be sourced. Thanks in advance for any help
Posted: Mon Jan 23, 17 7:08 pm
by Blue
In a foam filled cell you have to use a tube type sender, they come in several lengths depending on the height of the tank, and in different ohm ranges to suit the gauge you are using. Is your gauge the stock one or an aftermarket add on?
Posted: Mon Jan 23, 17 9:32 pm
by Aitch
Thanks for the quick response Blue. Gauge is aftermarket add on of unknown origin, I know GM gauges are 0-90ohms and Chrysler ones go to 130ohms I think but again, don't know the origin of anything on the car so would be helpful to speak to Terry so at least I'll know the make of manufacturer so can source the correct sender. To be honest I don't even know if I can get the sender out of this fuel cell yet I'm only assuming I can. As far as I've researched at the moment Summit Racing now do foam filled fuel cells with baffling that allows a pivoted arm sender unit with a float to be used that are made for them by RCI but that means a new cell from America and I've already found several companies that can make me a fully baffled aluminium fuel cell here so if I'm going to buy a new fuel cell I'll get one here, I'm just trying to avoid that if possible as a new sender unit is going to be a far easier and quicker fix than having a new fuel cell made for me and all the associated work that goes with adapting my fuel lines to fit it.
Posted: Tue Jan 24, 17 6:46 am
by shovelheadrob
The gauge is an Autometer, hopefully Tel will be along soon with any more info, I'll speak to him.
Posted: Tue Jan 24, 17 6:53 am
by shovelheadrob
Just spoke to Tel, he said it's the one that came with the fuel cell, which is a Jaz. HTH
Posted: Tue Jan 24, 17 6:57 am
by terryr
As far as can remember,the fuel cell came with the sender already fitted,I had the standard clocks in the car,maybe pull it out and see if its got stuck,think they worck with a float,also check your earths
Posted: Tue Jan 24, 17 1:05 pm
by Aitch
Cheers Rob & Terry, it's a jazz fuel cell. That's great, all I needed to know!

Posted: Tue Jan 24, 17 6:55 pm
by terryr
They are available on the jaz page,just make sure you get one compatible with your gauge
Posted: Wed Jan 25, 17 6:34 pm
by Aitch
All sorted thanks Terry, I've found a Jaz dealer about 20 miles away from me in Kent. Just got to pull the sender out and check it at the weekend, could be a sticky float if I'm lucky otherwise if alls well with the wiring at least I can get a new sender unit. Out of interest can you remember if the cell is a 10 or 12 gallon one?
Posted: Wed Jan 25, 17 9:46 pm
by shovelheadrob
The sender that is in there may not be compatible with the Autometer gauge, Terry had if wired to the in dash factory gauge & I put the Autometer gauges in the panel but never finished the wiring so I never got to test it, I also can't remember if the Autometer gauges come in variants to work with different senders, their website should tell you.
Posted: Wed Jan 25, 17 10:05 pm
by Aitch
Thanks for the help and getting hold of Terry for me Rob, I appreciate it. From the google searches I've done and the Jaz dealer I've spoken to Auto meter gauges are 240-33ohms and Jaz do sender units for that range, and the gauge did work fine then just stopped at half full (much to my disappointment) and I didn't really think too much of it as I hadn't driven the car for about a week meaning that I ran out of petrol, obviously down a tiny country lane! I'll check if it's the float that's just stuck and that the wiring's ok then order a new sender unit if needed. I only asked about the cells capacity as with the foam in it I've never managed to fill it with the same amount twice!
Posted: Thu Jan 26, 17 6:52 am
by shovelheadrob
Just carry a 10 litre container full of fuel, run it to empty & fill it up! Remember the stated capacity will be US gallons which don't go as far as ours.
Posted: Thu Jan 26, 17 2:54 pm
by Aitch
Rob, just a thought, Autometer do gauges in various ohm ranges but most commonly 240-33, did the fuel gauge work when it was wired to the factory clocks? If so I know Chryslers ohm range so it may save me trying to test the gauge or ordering a couple of units through trial and error. No worries if you can't remember. Cheers. Dave
Posted: Thu Jan 26, 17 5:58 pm
by shovelheadrob
I can't remember for certain but I think that I would have ordered a gauge to work with a stock sender as I assumed that the one in the fuel cell was designed to work with the stock gauge as that was what it was wired too. Disclaimer, I could be wrong though!
Posted: Thu Jan 26, 17 8:37 pm
by muzzydave
early ford /chrylser fuel gauges used 73-10 ohms range
been all through this on mine