Fuel Gauge for dummies

OK So i bought this.

http://www.ebay.com/itm/190616078781?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

I need a sending unit? Certain one?

I assume i just need about 40ft of wire and i'm good to go?

Anyone have a diagram on how to wire this up? Would appreciate it!

I bought a moeller gas tank to place in and i'll probably sell or junk my original Metal Tank.

Bri thank you a ton!

Bri892001 wrote: No problem. You're welcome. The interesting thing is that the "S" sender wire is actually a kind of a ground. The fuel tank sender, provides variable resistance to ground, depending on fuel level, and that's how it reads on the gauge. Also, the fuel tank, needs to be grounded to an actual ground, usually the engine block. Then the tank itself becomes a ground. If the fuel tank isn't grounded, the gauge won't work.

Well the tank is the Moeller 032719 everyone seems to buy.

Where would i ground it?

It seems like these tanks come with a sender, or is that just a brass cap? It sitting at home so obviously, i just need to look!

I was planning on doing this yesterday, but it was 5 degrees in my garage. SO i said No thanks.

I did look at the panel though, can i just piggy back off one of my other gauges for the "I", "B" and "G" ?

Yeah, there's a tanish yellow wire, i noticed that is already in the back of the boat and then ends right near the panel in the front, i'm going to try and use it, so I can avoid sending a new wire. it makes me wonder if the boat had a fuel gauge at one point.

I assume the center of the sender if where I attach? Then the prong on the outer part of the sender is where i attach to the engine ground? Can I just attach this to the negative on the rear light, to ground it?

Awesome, thank you, this was extremely simplified, it's overwhelming leaning under the dash on this boat and looking at the jungle of wires sometimes haha. Really isn't that hard once you break it down.

You went over my head there Peter.

Bri892001 wrote: turningpoint84 wrote: You went over my head there Peter. On the Ohm-ing or the butt connectors? Basically a good, solid clean ground wire running from the ground tab on the sender, to the block will have little to no resistance. Ohms is a measure of resistance. You can use a multimeter to check resistance. From the multimeter you put one meter wire on the tab, and one meter on the block, set up your meter to check ohms, if you have little to no resistance, you've got a good ground wire set up. A quick and dirty version of this is to check for continuity. That tells you if you've got a path, but not necessarily how good it is. You could start with that though, as it's often simpler to do with a meter.

No I fully understood that, the heat shrink rant lost me.

Even though i had a C+ average in EE, i actually do know what OHM's are haha.

Where are you guys connecting to the block anyways?.....I haven't looked where the actual connection point is.

I'll look closely, can be that hard, and on the butt splices, i was going to just hook up directly to where the light is wire is connected. What gauge are you using? looks like at least 14.

NM I read your thread, 10ga....seems kind of hi?

Also bri thanks for the patience, i wont be tackling this until July, just want to make sure i have it correct!

turningpoint84 wrote: on the butt splices,

I highly advise not using the cheap "hardware store" version of crimp connectors. The marine envirorment is pretty harsh and in the long run you will have problems.

I aslo certainly hope you are using marine grade wire. Each strand is tin plated to prevent the copper from corroding.

I was going to help you out on this Peter so I went out and looked at my boat.It is all in pieces again so it's easy to look,but now I'm confused. There are 3 wires going to the back tank area,a ground,stern light and fuel gauge. The problem is on those models the blower was mounted to the port side next to the gas tank so I should have 4 wires. I suspect that I pulled it out years ago but cannot remember. You might already have a wire going to the back.

Gary S wrote: I was going to help you out on this Peter so I went out and looked at my boat.It is all in pieces again so it's easy to look,but now I'm confused. There are 3 wires going to the back tank area,a ground,stern light and fuel gauge. The problem is on those models the blower was mounted to the port side next to the gas tank so I should have 4 wires. I suspect that I pulled it out years ago but cannot remember. You might already have a wire going to the back.

SO a fuel gauge wire was a factory install? Just not the fuel gauge?

It would make a lot of sense, the wire is a yellowish brown one for me, that's blank.

My blower I'm moving so it's under the tank next to the rudder box. The newer plastic tank has a little more clearance.

Also this will allow the blower to actually clear the fumes from the engine compartment!

turningpoint84 wrote: SO a fuel gauge wire was a factory install? Just not the fuel gauge

Peter,
I would have to say that when the factory installs a gauge, they would wire it as well. Without the wiring, I really don't feel the gauge would work.

turningpoint84 wrote: ... My boat never had a fuel gauge, I'm adding one, but i figured maybe they just ran the extra wire, IE they didn't custom wire each boat, they just had a factory wiring done, and if the wire wasn't used it was just a dead one. Why else do i have an extra wire sitting around not being used? All i was asking was when they wired these boats did they wire the boat to have all wires in case the customer ordered every option, and if they didn't the extra wire wasn't used or did they custom wire the boat to how the customer ordered it?

I saw this one, and decided to leave it alone. Because, I don't actually know for a fact how boats of your era where factory wired.

However, I'd say your theory is highly probable. This happens all the time on the automotive side. I've been poking around researching adding fog lights and trailer hitch wiring to various different trucks I'm shopping.

I'm finding quite often that for fog lights, the kits are literally just the lights and the switch, all the wiring is there even for trucks that didn't come with them. It looks like Nissan Frontiers and XTerras have wiring for the hitch in every truck, but just leave out the last 2 feet or so, in non-hitch trucks, so you just buy this mini harness for the trailer plug.

I know that my boat has some accessory switches, and the start of wiring runs, for dash accessories that were never installed.

Brian is correct, to some extent. I've seen stereo wires run on boats without one. I also remember a thread on PN from way back about it too.