Please help!?!1961 Jaguar, Mark IX fuel sending unit

Has anyone had luck with the sending units that are being sold for the Mark IX?
I have purchased two and haven’t been able to make either one work. The angles and curves are not even close to the original. I would love to know if anybody has had success with these new units and if so, directions on how I can do it, so I don’t ruin a third unit…
Thank you in advance! Any advice or help is greatly appreciated…

Hi, I think you are asking about the fuel gauge in the tank. I have yet to have experience with any new unit but are currently working through getting the gauge working for both tanks in the Mark IX.
I sent my dash gauge to an instrument repairer, and it is good. I was advised that the sender in the tank should have 3 ohm resistance on Empty, 43 ohm half full and 83 ohm Full. Some multimeter have times 10 ohm scale which would read 1 through to approximately 9 at Full.
I gather it is easy to get things wrong and burn out a coil in the dash instrument gauge. I hope these figures assist in identifying the problem.
Regards
Matt

Hi Matt – thank you for your reply and concern. The issue is with the float rod and the angles to get it to where it needs to go. The new ones are not bent like the old ones were. Everything else should be the same, as far as the tolerances go.
Thank you very much for your response. Maybe I’m the only one having issues!
Regards-Jim

I have to believe that somebody has bought one of these fuel sending unit for their gas tanks. I just want to know what you did to get it in. Did you have any issues? Do I need to be aware of anything? Any responses sure would be appreciated. Thank you in advance!

Hi Jim,
I haven’t purchased replacement fuel sending units, but I can offer a photo of my original from the port side fuel tank. Your original should look like this… does your replacement look like this or is it different?

My mechanic supposedly tested my original sending units before he installed them in the rebuilt fuel tanks, but I get nothing but an “empty” reading on my fuel gauge… either fuel tank. My guess is that I have a wiring issue somewhere or a defective gauge. The gauge will be easy to test, but now that the sending units are installed, those will be a bit more difficult to test.
Best of luck,
Jay

Thank you very much, Jay! Just wondering what year is your model? I have a 1961 and I think they may be different… Thanks again buddy!
Jim

Gents,

My research indicates the Fuel sender is the same throughout the MK7 to MK9,
at least they are advertised that way…and very expensive

There is a LH (the short one I think), and a long one

I have remaining 2 short ones and one long one.

The main issue with (these) ones is the thin metal float is unacceptably corroded

They also tend to get frozen or corroded float arm, especially steel within the alloy body

As a (in a previous life) technician, I have repaired quite a few gauges and senders (as have others on here), partly due to NLA or very expensive and dubious aftermarket parts

I will start by saying dont throw away the old ones

I have decided that I am going to revive these old units by silver soldering a new float onto them.

I just have to find a suitable source of replacement floats…any ideas ?

It usually possible to repair the electrics inside

The float arm wire could be replaced by a substitute

I will (try to remember) to take some pics next to a ruler, and post them up, if I do it today, I will remember !

at the OP, the gauge should hit max if the earth wire is earthed

if not, see if 12V is present at the relevant gauge terminal, earth the other,

Your mechanic should know how to do all those things in about 5 minutes

Hi Tony,

Believe it or not, the original float in my Series 3 E-Type was a wine cork, which was deteriorated by the time I got the car. If worse comes to worst you could use one of them. However, I took a sheet of brass and rolled it up, cut a couple of disks and soldered it all together to make a new float. Since you’re a tech you probably know your way around a soldering iron, so that shouldn’t be that tough for you.

Since you are willing to modify one to fit, if you search Ebay for “Jaguar Fuel Tank Sender Assembly” you might get some raw materials from an XJS or XJ6.

I do believe it cause my S1 XJ6 had corks

probably cheaper than soldering

as you know the arm is also often soldered, or maybe brazed together to make the right shape, its very “hard” wire, I will measure its diameter

Hi Jim,
My Mark IX is titled as a 1961, but according to the heritage certificate, it was born on May 12, 1960. It may well be that my floats are sunk; I know my mechanic tested the resistance through the range, but I’ll have to check with him to see if he tested the floats.
Jay

Thank you for the response, Jay! If you end up installing one of the new sending units, please let me know. I need one for my passenger side/right side and just want to make sure that they actually fit the tank before I go, through, all that is necessary to remove the old one, and reinstall a new one, without leaks! Again, if anyone has used a new replacement, please let me know your opinion on it! Thank you in advance…
Jim