Technical Ford gauge/sender issue

I have a frustrating issue with the fuel gauge in the project. New 80 ohm sender from Tanks hooked to 68 Ford truck gauge. Ground the sender the gauge goes to full. Pull the sender out of the tank and rotate the float to the full position the gauge goes to 1/2 at around 8 ohms. Ordered a new ICVR and installed that since the regulator was a OE '68 piece. No difference.
The oil gauge works both before and after the regulator change. The temp sender is not working but will peg when grounded. The engine block and the tank sender have a seperate ground to the frame.
Is this a ground issue? It is driving me nuts.

 

Try hooking up the oil gauge in place of the fuel gauge going to the fuel sender and see how that gauge swings when you move the fuel sender. If it moves the same, the problem would be the tank unit.

 

@Crazy Steve , any fuel gauge thoughts?

@squirrel , remind us what ohm range sender this vehicle's gas gauge requires?

 

I have an old potentiometer that I pulled out of an 80's Cadillac temperature control which I use in place of the sending unit. I measure the resistance value from empty to full to determine what sending unit I need. Also, look inside the tank to see if there is a baffle preventing full movement of the sending unit.

 

An 80 ohm sender won't work with your stock gauge. Ford senders for that era were 240 ohms empty and 33 ohms full. Chevy used a 0-90 sender with a magnetic gauge. Ford used King Seeley gauges and worked entire different front Gm. Have a serious talk with the folks at Tanks.

 

@deucemac , will these work, or is the dash gauge incompatible with this type sender?
https://www.summitracing.com/search...nge/240-ohms-empty-33-ohms-full/universal/yes

 

What deucemac said... you have a King-Seely fuel gauge which wont work with aftermarket senders...

 

@vtwhead ,
Looks like Rockauto.com has what you need:
https://www.rockauto.com/en/catalog...+l6,1119721,fuel+&+air,fuel+sending+unit,4436

 

I have contacted Tanks and will see what they offer. Clearly their site says the Ford gauges use a different unit. I can't imagine that I am the first to come across this. I appreciate all the input on this and will let you know how this turns out.

 

Seems as though it might. Ohmeric value is right, just has to fit the hole.

 

Ford for that year is 73 /10 ohms , correct?

 

Yes, that's what I was thinking. Fords thru the 60's and up to the late 80's all use 73 / 10 ohms

 

See the Rockauto item in post #8. I'm not sure of the ohm range.

 

Last resort if you want to use that sender and gauge. I used it on my '41 p/u because I didn't want to pull the bed off. Mine is a S/W 240 ohm sending unit with a stock '41 fuel gauge, it's been working good since I put it in.

Auto meter Fuel Bridge:
https://www.summitracing.com/parts/atm-9109

 

70/10 is El Correcto

 

Here's another vendor with O.E. replacement fuel sender:
https://www.npdlink.com/product/sending-unit-fuel-level/135948/50532

 

OK I am confused now (my normal state of mind lately) The gauge that is in question is from a 1968 Ford F500. When did Ford stop using King Seely pieces? Can one tell by the gauge itself?

 

All I'm able to find out with a quick search is that they stopped using the King-Seeley gauges in the late '80's...

 

Have you tried your local NAPA store?

 

I seem to remember reading that King-Seeley gauges go to full scale when the power is off as compared to resistance gauges that go to low scale with the power off.

 

Waiting on Tanks to get back to me. They had responded only to ask what gauge I had for the gas sender. I had clearly spelled it out in my initial email that it was from a 68 Ford F500 truck. Could that need any more explanation? Ha!
That was on Friday so this will wait now until this coming week.
They offer the same aftermarket sender that I have currently but in the 240 ohm range. Hoping they will come thru with an offer to help solve this issue.

 

Start looking for an original NOS sender...

 

Nope 245 empty and 33 full

Ford discontinued use of King Seeley gauges in 1986 when they went to magnetic style gauges. I was doing tune up, A/C, and electrical at a Ford store and we had gauge and sender problems galore with the magnetic system for some time until Ford figured out what they did wrong. I rarely if ever had problems with King Seeley, and for a couple of years we wished Ford had never changed.

 

I just opened up a '68 Ford service manual, it's for cars not trucks ... but any I've worked on were the same. Regarding Ford fuel gauges for '68 the manual says 10 ohms should read full and 73 ohms should read empty.

 

Nope

 

You are correct . The tanks web site says the same thing , it’s 73/10 . Mmmm… maybe Tanks has no idea what they are doing and the Motors manual is lying to us and experience means nada. Besides it is not 245 try 240 ohms.

 

OMG! 240, 245,33, 73,10 you guys are killing me I'm going to build an electric hot rod and be done with this ****

 

Just fill it up, measure the resistance of the SU, gonna be around one of those numbers

 

did that already. It is a 73/10 sender.

 

Mine must be and odd Duck then. 1967