YAMAHA speedo fuel gauge connection

Anybody connected one of these:

http://www.yamaha-motor.co.uk/accessories/accessories/acc_details.jsp?grpId=354&productId=1975$2$Digital%20In&year=-1&pageNr=1&accessoryId=9552

to one of these:

http://www.quaywest-chandlers.co.uk/Products/product_pages/p_Plastimo-Electric-sending-unit-for-fuel-tanks_PlastimoElectricsendingunitforfueltanks.html

Is it just two wires?!!

....not a Yamaha one specifically but they are all pretty much the same. Yes it is just two wires from the sender to the gauge; the sender basically measures the resistance between two points. As the float in the tank rises and falls it increases/decreases the resistance in the circuit which is shown on the gauge (the gauge acts like am omh-meter). Then you just need to wire the gauge to the battery.

I assume all Yamaha stuff works together but something to bear in mind is that you need to get the right sender - I bought stuff from Faria (or however its spelt) and got the wrong guage for the sender. Now the gauge reads backwards so when it's empty it says its full and visa-versa. (It it still quite accurate though!)

great! thanks, that's just what I needed to know!


If you reversed the two wires wouldn't yours read correctly? or not at all?

Yes i have wired a fair few. we use wema senders and get them to make it to usa spec. to get it to read the right way round. or if not there is some swiches on the back of the gauge to make it read the right way round. if you need any info just ask.

RIBBOI

great thanks - will keep track of this thread jus incase!

If you reversed the two wires wouldn't yours read correctly? or not at all?

No, it would read the same. 200 ohms reads the same no matter which direction you read it.

You need to adjust the gauge so that it sees 220 (or whatever it is) as full, and zero as empty, or vice versa. If there is no way of doing that, you either replace the gauge, replace the sender, or live with it.

Note that there are different standards for senders. At least two different resistance scales, and I'm not sure the polarity is the same on all of them (i.e. is it max or min resistance at full?)

jky

Thanks for the replies! - right, not sure if anyone will be able to answer this, but now i'v got my plastimo gauge, 2wires coming out, and am ready to install it, but all I have in the way of wiring diagrams for the Yam gauges is the set-up paper card that tells you which way to through the microswitch for sender type etc.

Having lied on my back upside down inside my console looking up at the back of the gauge, I can see the wiring loom coming from the gauge and the connections connecting that to the incoming ignition wires etc. Do the sender wires link into the empty bullit type connections that come off the loom?! (thats going to be trial and error seeing if any of them work - or maybe just error!!)- or does the sender wires go directly into the back of the guage itself? - there appears to be a rubber bung where all the wires enter the back of the guage in a loom, but there also appears to be some empty holes, in the bung which look as if they are for additional wires?

I realise this may not be an answerable question over the forum, but maybe some amazing and helpful person has a pdf wiring diagram of the back of the guage!?!!? - I have tried google but no luck!

Might be worth taking the gauge out and having a look close up - the terminals are normally marked but are quite hard to see unless your up really close in good light.

Be very careful when it comes to "trial and error" with a fuel gauge. If you short it out you could cause a rather large bang as you ignite your fuel tank.

Might be worth having a read of this before you go any further.

http://rib.net/forum/showthread.php?t=13930&highlight=fuel+sender

Pete

thanks for the link - interesting! - I found an american yamaha outboard forum where someone kindly emailed me the wiring diagrams for both the tach and speedo gauges - which has made it immediatley clear which wire goes where - it turns out (for the fuel sender) it is the BLACK and the WHITE - currently as I have no fuel guage the two have been connected together with a bullet connector so the gauge always reads full - hence, why when I looked at the back of the gauge the other day I couldn't see any spare wires! - anyway forgot the keys to the boat when I went to see if the sender would work today! so couldn't test - but at least I know the wires are there ready to be connected!:)

If anyone searches this forum with a related subject in the future and needs the diagrams for YAMAHA guages, please drop me an email/pm and I can send them over!

Cheers

Chris