Fuel gauge reads the wrong way round

[Tim M]

I've just wired up a new fuel gauge on my boat. The tank already had a sender in it which I have connected the new gauge to. However, the gauge reads the wrong way round - when the tank is full the gauge says it is empty and visa-versa. I'm pretty sure the gauge is OK - only just bought it.

Is the solution as simple as swapping the two wires that connect to the sender round? I may well have wired it wrong - on the sender is the "sender" terminal likely to be the pin sticking up on the middle? (I assumed it was and the screws at the side were ground)

[Cookee]

There are two types of sender - US and European, you'll need a US one on a Mercury! Wema do them to order.

[craig_c]

We had the exact same problem on a previous boat, we did try swapping the wires round on the guage but it did not work... easiest way to look at it is if sum1 nicks your boat, they think they have got a full tank!!!

[jyasaki]

FWIW, the difference (I think) between the US and European senders is the resistance range. Shouldn't have anything to do with guage polarity.

jky

[Matt]

There's 3:
10-180 ohms
240-33 ohms
90-0 ohms

For obvious reasons, the gauge and sender have to match

[Tim M]

Right....It seems odd then that it should give me a correct reading albeit the wrong way round. I'll have to find out what range the sender is.

[Matt]

Not really.
90-0 is specifically for the vdo range of tube senders.
The other 2 are close enough to the inverse of each other for government work.

[Tim M]

It's not a Mercury gauge btw. Can't remember the make without checking but from memory it begins with F.....

The old gauge was also made by them (replaced cos it was rusty and horrible)...weird

[Matt]

Faria. Can be bought from asap supplies who usually have stock.
http://www.asap-supplies.com/
They sell both european and us resistance ranges
Link to one of the gauge ranges:
http://www.asap-supplies.com/toc.php...BY_STYLE&prod=

[jyasaki]

Try looking here:

http://www.teleflexmarine.com/cgi-bi...=us&link2=1047

and select Fuel Systems from the menu below the really bad drawing.

This thing is not rocket science; shouldn't be all that hard to troubleshoot.

jky