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fuel tank sender
ayoungman - 10/1/06 at 02:57 PM

Can I use any float based fuel sender unit. I don't yet have the fuel gauge so I have'nt got a clue if it is a must buy soon option or not. Once the tank is in I really wont want to remove it to fit the sender at a later date.

mookaloid - 10/1/06 at 03:11 PM

As I understand it the float/sender unit in the tank must be appropriate for the gauge.

otherwise it won't work very well - if at all.

Cheers

Mark

Hellfire - 10/1/06 at 03:18 PM

Just about what Mark says - they have to be paired if they are to work properly.

02GF74 - 10/1/06 at 04:06 PM

true and not true.

usually the sender is a variable resistor and is connected in series with the guage, whcih in effect is a ammeter.

if you know the rnge of restistance for the sender and the range of amps for the guage you can with some additional electrickery interface the two together.

I have two defender guages for each underseat tank which have series senders (land rover talk) that are not compatible; I made simple op-amp circuit to make it workable; it is still non-linear but is usable; ah yes, forgot to say that both the sender and guage linearity may not be compatible.

In short, use compatible sender/guages to avoid problems.

Hellfire - 10/1/06 at 04:22 PM

quote:
Originally posted by 02GF74
true and not true.

In short, use compatible sender/guages to avoid problems.


Ah-hem

ayoungman - 12/1/06 at 10:54 AM

I was looking at landrover series senders the other day. I could use a variable resistor and then 'tune' it to match the fuel gauge. I've got a spare sender from the old tank on my 109 to play with.

thanks guys, I'll have a play and let you know how I get on

02GF74 - 12/1/06 at 01:35 PM

quote:
Originally posted by ayoungman
I was looking at landrover series senders the other day. I could use a variable resistor and then 'tune' it to match the fuel gauge. I've got a spare sender from the old tank on my 109 to play with.



ah, if only life was that easy. to save you some time, here is some stuff you should know.

series guages were wiredto the voltage stabiliser so effectively run on 9 V (Defender guages run on 12 V).

next the senders, typically range is 30 - 300 ohm but there are different flavours, that my just apply to military one. I have senders that work in opposite way; high resitance when empty whereas other is low resistance when empty.

so quite a few combinations. there is some non linearity i.e. the guage can read full for a long time even though it isn't then suddenly start dropping to empty - don't really have a solution for that one.