Fuel gauge reading

Morning

my 1966 2A has had an alternator fitted, thus replacing the original dynamo I believe.

Currently the fuel gauge reads backwards (according to the previous owner as a result of the change dynamo to alternator) so full = empty / empty = full.

Would this be true or is there another reason for this - perhaps faulty sender unit / incorrectly wired?

Any thoughts would be appreciated.

Cheers
Paul

might be as dynamo is positive earth and alternator is negative iirc, surely then if you wire it the other way round it will work properly

honolulujoe said:

might be as dynamo is positive earth and alternator is negative iirc, surely then if you wire it the other way round it will work properly

Click to expand...

It would appear that the previous owner (just contacted him) had tried this to no avail. I will have a look tonight when I get home. Seem to recall that there is only one wire to the sender but perhaps two connection points on the top of it - but can't totally be 100% sure about that.

The PO also suggested the following:
(swap wires). Only thing I could think of is potentially
buying a Series 3 gauge and putting that into the tank, and the wire
onto that - because Series 3's ran with the same polarity Betsy does now
- so that could read the right way. One last thought I had, but never
got round to doing was the bend the metal arm backwards (the one that
sits within the tank) so that the float goes backwards if that makes
sense? If you take the gauge out of the tank and move the arm up and
down and see which way the needle moves on the dial, could be a way of
making the float read in a way which matches the dial - not 100% sure
though.

Not sure I want to go to the faff of bending sender unit arms etc - perhaps I should just keep her half full

peejaysea said:

It would appear that the previous owner (just contacted him) had tried this to no avail. I will have a look tonight when I get home. Seem to recall that there is only one wire to the sender but perhaps two connection points on the top of it - but can't totally be 100% sure about that.

The PO also suggested the following:
(swap wires). Only thing I could think of is potentially
buying a Series 3 gauge and putting that into the tank, and the wire
onto that - because Series 3's ran with the same polarity Betsy does now
- so that could read the right way. One last thought I had, but never
got round to doing was the bend the metal arm backwards (the one that
sits within the tank) so that the float goes backwards if that makes
sense? If you take the gauge out of the tank and move the arm up and
down and see which way the needle moves on the dial, could be a way of
making the float read in a way which matches the dial - not 100% sure
though.

Not sure I want to go to the faff of bending sender unit arms etc - perhaps I should just keep her half full

Click to expand...

think mr churchill109 has answered it in your other thread. For ease I have copied it in below

"Re: Backwards fuel gauge: I suspect that you have a later type fuel sender with an earlier type gauge - my 1954 Series I is set up that way at present and it's annoying. Might want to see if you can source a used earlier sender for the petrol tank - used as new are no longer available.

Re: Alternator: Not likely to have caused the problem above. TBH it's a good addition - did that on my 64 109 long ago and never looked back. While the dynamo is picturesque the measly 20 amps it can put out at running speeds is just not enough with lights/wipers/heater (as is needed here 6 months of the year). Alternator is likely 40-60 amps and will charge at idle."

Thanks guys - not too sure if it is forum protocol to keep everything "Betsy" related in the one thread or to ask questions (i.e post new thread) as and when I have a Q?

Anywho - also found this link re senders / fuel gauges: Series Land Rover Fuel Gauges and sender units

which was interesting.

cheers
Paul