fuel sender & guage

[Olive Drab]

Righto time to ask the brains trust again.
my fuel guage works backward,
F= F/all
E= enough
Is it possible I have a positive earth sender in a negative earth vehicle?
I have even used the other side of the voltage regulator, the temp guage side to see if this changes, stays the same.
just asking before I fork out for a new sender or have I missed something.
What voltages should I have @ empty and full when measured at the regulator?

[Blknight.aus]

youve got the wires on the gauge backwards OR youve got a flipped sender, pull the sender and put the float arm on the other way.

[Olive Drab]

tried the wire swap on the guages. i'll pull the sender out tomorrow and check. Looking at it when i repaired the tank the sender looks as if it can only go in one way but I'll re-check I did the install and repair after an arvo shift could be the sleep monsters got me
thanks Dave

[RobHay]

youve got the wires on the gauge backwards OR youve got a flipped sender, pull the sender and put the float arm on the other way.

What he said........No such thing as a positive earth guage, only incorrectly wire guages...........or incorrectly mounted sender units:p

[JDNSW]

Unfortunately Rob, while there is no such thing as a positive earth gauge - the gauge and sender changed when they went from positive to negative earth in 1967. The senders and gauges are not compatible, and the senders work in the opposite sense. So you will get this effect by mixing the gauge and sender types.

There are two types of gauge - the earlier type operates by the repulsion of two coils and shows instantaneous changes in fuel level, and does not use a voltage regulator. The later type uses a thermal type gauge, same as the water temperature gauge, which moves only slowly, and has an external voltage regulator, which in the 2a is on the bulkhead behind the instruments, and on the 3 is on the back of the speedo.

Neither gauge is polarity sensitive, so the reverse reading can only be given by using the wrong sender with it. I'd have to have a look at the sender to see if it is possible to have the float set up to give reverse operation, but I do not think it is possible.

John

[Olive Drab]

with the regulator on the bulkhead. 4 pins, 2 for the fuel, 2 for the temp. I'll post what I find even if it makes me look silly:)

[Olive Drab]

pull the sender out, the casting on the sender won't let the float rotate the other way, switched the wires again, no result. Double check earth circuit-extra wire from sender to body=same condition. i'll put up with it for now will borrow the sender from my brother-in-law's project. Still thinking toward positive earth sender. Will post result when i have tried the other sender.

[JDNSW]

Going back to my post of the 18th, you must have sender and gauge that do not match - could be either one is wrong, but if you have the instrument cluster with the temperature gauge, then it is likely that your gauge is the later one (which is correct if you have the cable operated wipers), since it is unusual to change gauges rather than clusters. Most likely the tank and hence sender has been changed for an earlier one.

John

[Olive Drab]

think your right about the sender JD. previous owner was a fisherman and got sick of fitting landy tanks, hence the comodore tank in the tray when i got it.
So if the other sender fixes the problem there will be a pos. earth sender free to good home should anyone require it.

[Aaron IIA]

It is possible to convert the sender to work from one style of guage to the other style of guage. Take the top off of the sender to reveal the resistive coil. At one end of it, it will be connected to a stud which goes through the housing to connect to the wire which goes to the guage. To convert the sender, you need to connect the other end of the coil to the stud. Do not reverse the physical direction of the coil, as this will have no effect. You need to run a wire from the opposite end of the coil (from what it is now) to the stud.

You want to end up with a sender as follows:

Opposing coils guage (instant, early type)
Tank empty = min resistance (about 0 ohms) sender to earth
Tank full = max resistance sender to earth

Thermo type guage (slow to react, late type)
Tank empty = max resistance
Tank full = min resistance

I dont know if the guage will be calibrated very accurate if the reversal process is conducted, but at least the needle will swing in the correct direction.

Aaron.

[JohnR]

Heh Olive Drab,

Both Aaron & JDNSW are eight in what they have said.

The early gaues (Twin Coil) Can be distinguised by two terminals on the back and another two BA4 nuts which look like terminals but are not. These gauges run 12v and do not require a voltage regulator. They have a "B: for battery, a "T" for tank unit and they also require a earth to the chasis. You can also tell a twin coil gauge from the front when you turn the ignition key on it will jump straight to it's position very quickly. These gauges are 0 Ohms Empty and 75 Ohms full

The later gauges are Bi-metal gauges they only have the two teminals on the back. One terminal from the voltage regulator (which output a switched 10v they best way to test this is with a test light, it should blink a bit duller than a constant 12v) and the other teminal to the tank unit. These gauges can also be spotted by the fact that when the ignition is turned on it can take up to 2 minutes to get to its correct position. These gauges are 240 Ohms Empty and 19 Ohms full.

You can revearse the send as previously described but as you can see the values are very different so it will go in the right direction but not be in the least bit accurate.

You either need to find the right sender or get your one rebuilt (easy to do if you know how) :cool:

Just a after thought you said something about a commodore tank??? It wouldn't happen to have a holden sender in it would it??? :eek:

PM Me if you need more help.

Cheers,

[Olive Drab]

Definitely the later 2a with the regulator on the bulkhead. Am pretty sure has landy sender as well. the previous owner went through several tanks during it's life on the beach, and by the state of the screws i imagine he never bothered keeping the original sender with the car.
I'll be seeing you soon John

[digger]

you havent got a dodgy fuel guage, its a wallet guage, when the tank is full, your wallet is empty, but by the time the tank empties, your wallet better be full!!!

using that principal was the basis for the wallet/fuel guage for landrovers....
see http://www.aulro.com/afvb/remlr-general/58690-new-fuel-guages.html?highlight=fuel...


cheers
digger

[peterg1001]

There are two types of gauge - the earlier type operates by the repulsion of two coils and shows instantaneous changes in fuel level, and does not use a voltage regulator. The later type uses a thermal type gauge, same as the water temperature gauge, which moves only slowly, and has an external voltage regulator, which in the 2a is on the bulkhead behind the instruments, and on the 3 is on the back of the speedo.

Neither gauge is polarity sensitive, so the reverse reading can only be given by using the wrong sender with it. I'd have to have a look at the sender to see if it is possible to have the float set up to give reverse operation, but I do not think it is possible.

John

Hi John, I'm having an amusing time with the fuel gauge, so I thought I could restart this thread and follow on from your comments above.

Start point - the fuel gauge isn't reading right, it always reads 3/4 full or above.

Known facts:
The gauge cluster is a Jaeger 560744, which corresponds to a IIa suffix D on. It reads empty when a 300 ohm resistance is put in series with it, full with zero ohms. It doesn't matter which 12v polarity is applied to the gauge.

The sender reads zero ohms on empty, 70 ohms full. It has part number 5347/07 on it, which corresponds to 519838 in the parts manual, which corresponds to a IIa up to suffix C.

It seems clear I have a sender/gauge mismatch.

Can you, or anyone, confirm that I should install sender 555844 to sort out the problem?

Thanks in advance,
Peter

[Johnno1969]

Unfortunately Rob, while there is no such thing as a positive earth gauge - the gauge and sender changed when they went from positive to negative earth in 1967. The senders and gauges are not compatible, and the senders work in the opposite sense. So you will get this effect by mixing the gauge and sender types.

There are two types of gauge - the earlier type operates by the repulsion of two coils and shows instantaneous changes in fuel level, and does not use a voltage regulator. The later type uses a thermal type gauge, same as the water temperature gauge, which moves only slowly, and has an external voltage regulator, which in the 2a is on the bulkhead behind the instruments, and on the 3 is on the back of the speedo.

Neither gauge is polarity sensitive, so the reverse reading can only be given by using the wrong sender with it. I'd have to have a look at the sender to see if it is possible to have the float set up to give reverse operation, but I do not think it is possible.

John

Yeah, I observed just that when I put a gauge from a Series III into my IIA. Had to have the right sender, if I remember correctly.....

[JDNSW]

Hi John, I'm having an amusing time with the fuel gauge, so I thought I could restart this thread and follow on from your comments above.

Start point - the fuel gauge isn't reading right, it always reads 3/4 full or above.

Known facts:
The gauge cluster is a Jaeger 560744, which corresponds to a IIa suffix D on. It reads empty when a 300 ohm resistance is put in series with it, full with zero ohms. It doesn't matter which 12v polarity is applied to the gauge.

The sender reads zero ohms on empty, 70 ohms full. It has part number 5347/07 on it, which corresponds to 519838 in the parts manual, which corresponds to a IIa up to suffix C.

It seems clear I have a sender/gauge mismatch.

Can you, or anyone, confirm that I should install sender 555844 to sort out the problem?

Thanks in advance,
Peter

Yes, although I can't confirm the part number as I am overseas.

John

[peterg1001]

Known facts:
The gauge cluster is a Jaeger 560744, which corresponds to a IIa suffix D on. It reads empty when a 300 ohm resistance is put in series with it, full with zero ohms. It doesn't matter which 12v polarity is applied to the gauge.

The sender reads zero ohms on empty, 70 ohms full. It has part number 5347/07 on it, which corresponds to 519838 in the parts manual, which corresponds to a IIa up to suffix C.

It seems clear I have a sender/gauge mismatch.

Can you, or anyone, confirm that I should install sender 555844 to sort out the problem?

OK, it's confirmed. Sender 555844 reads 280 ohms empty, zero ohms full and matches cluster 560744. My fuel gauge now works.

Peter

[JohnR]

It is possible to convert the sender to work from one style of guage to the other style of guage. Take the top off of the sender to reveal the resistive coil. At one end of it, it will be connected to a stud which goes through the housing to connect to the wire which goes to the guage. To convert the sender, you need to connect the other end of the coil to the stud. Do not reverse the physical direction of the coil, as this will have no effect. You need to run a wire from the opposite end of the coil (from what it is now) to the stud.

You want to end up with a sender as follows:

Opposing coils guage (instant, early type)
Tank empty = min resistance (about 0 ohms) sender to earth
Tank full = max resistance sender to earth

Thermo type guage (slow to react, late type)
Tank empty = max resistance
Tank full = min resistance

I dont know if the guage will be calibrated very accurate if the reversal process is conducted, but at least the needle will swing in the correct direction.

Aaron.

What you've said is correct Aaron but the calibration will be out and if you convert a twin coil to a Bi-metal it is likely to burn it out. the reason being:
Twin coil E-0 Ohms F-75 Ohms
Bi-Metal E-19 Ohms F-260 Ohms

Yes they will go ing the right direction but not calibrate correct. Also if you put 0 Ohms on a Bi-metal for to long it will fry.

PM Me if you want a solution to the problem. (No spruking allowed ;) )

And JDNSW, What do you do for a crust you know you stuff about gauges???

Cheers,

[JDNSW]

And JDNSW, What do you do for a crust you know you stuff about gauges???

Cheers,

Not quite sure what the question is. But I am a retired geophysicist, which is not really relevant. What is relevant is that I have been messing about with electrical gadgets for sixty years, since before starting high school, and have a collection of books on old automotive technology from the 1900s, to the 1950s and newer.

John