I owned one of those kits and reconsidered it. Blue Seas makes great stuff and a few here have the same set up and like it. I resold mine to "Step Up Here". I think it would be good to have if you have an involved electrical system with a lot of house loads. I currently only have a pair of bilge pumps and a GPS/Sounder and found it was EASIER and SIMPLIER to just run two 1000 MCA starting batteries with the typical 1 BOTH 2 OFF switch with 1 gauge cables between the engine, batteries, and switch. If you're hanging out on the hook playing the stereo etc, switch it over to just one battery leaving the other fully charged for starting.

You don't want it on all the time as it will drain battery over time. Its not just a gauge, it usually has a light also.
Often they are on a momentary switch but it is hard to pump gas and look at the gauge by yourself. Mine is on an on/off switch and it freaks passengers out when we're 60 miles out and the gauge says Empty!

You can connect them to the Ignition Key switched power (purple?).

You say "grounded thru a switch". that would not be right if true.

I took another look at it, and it's a black wire going to the switch...which means it's hot.

Smh...

I also discovered that the bilge wasn't getting power because it was disconnected from the manual switch, AND it's spliced with the bow bilge...yes, you hit the switch and they both turn on.

Smh....

I got a 3-way for the stern bilge, and the wiring instructions are all wrong (the built in circuit breaker is wired to the negative post)

Smh....

Thank God I've been reading the 12v bible and chatting with you guys.

basic boat wiring color codes:
Black= 12 volt ground
Red= 12 volt positive
yellow /red stripe= start circuit
grey=tach signal
blue=temp sender
tan=temperature
purple=key on 12 volt positive
tan/purple stripe= alarm circuit
pink=fuel level sender
green=common bonding ground wire


to wire a fuel gauge, you have a purple wire(key on power) to the B+ terminal, black wire to the B- terminal, pink wire to the sender terminal. The pink wire goes to the fuel tank sender, the sender has a dedicated ground wire, it will be either black or green. It will attach at the fuel tank usually under one of the fuel tank sender mounting screws

Maybe these diagrams will help:
http://i92.photobucket.com/albums/l4...psfldv5nzj.jpg
http://i92.photobucket.com/albums/l4...pslc9f46xv.jpg
http://i92.photobucket.com/albums/l4...psby3fhtz3.jpg
http://i92.photobucket.com/albums/l4...ps4fhznzxa.jpg
http://i92.photobucket.com/albums/l4...psnvedyiwt.jpg
http://i92.photobucket.com/albums/l4...psnvedyiwt.jpg
http://i92.photobucket.com/albums/l4...ps9aeals3j.jpg
http://i92.photobucket.com/albums/l4...psuyfnxxr6.jpg

I saw those, but also saw a third yellow-ish wire going (???)...would that be the tank grounding wire? Also, when I tested the sender wires with a light, my voltage meter bottomed out (it was working fine before)

^^^ These were ESPECIALLY helpful! THANK YOU SO MUCH! I finally figured out how to PROPERLY access the back of the gauge panel and was able to take of picture:

http://i284.photobucket.com/albums/l...g?t=1427052032

The new fuel gauge doesn't have a post for the light wires, but a spade terminal. I should probably use a double male, single female connector...splicing the gauge wires to one, and leaving the switch wire as a single?

I don't understand your question.... The gauge gets a switched positive from the ign switch OR a toggle if you prefer, the. It is grounded through the sending unit which is then grounded to bat neg.
Then the light for the gauge gets wired.... Often but not always the light has a switched positive and a constant ground

That wire you have labeled as "to switch (I thought it was black)" is not FOR the fuel gauge... It it most either taking power from that circuit (which spans the lighti circuits of ALL of your gauges) and using it elsewhere OR supplying power to turn on the lights.... You can remove it and verify that the gauges still light up.

On the gauge in your picture the black and red wires at the bottom almost definately are routed to the sending unit... Red is fuel level and black grounds to one o the screws mounting the sender.

A yellow wire at the tank does not belong there... The only other wire that should be there would be a green bonding wire.... Would connect to fill port, tank, and engine block along with any other major metal component or thru hull hardware.

I need to go from one post (on old gauge) to one spade for three wires. This is what I thought I should do (let me know if I'll blow it up instead):

http://i284.photobucket.com/albums/l...g?t=1427144008

Ohhhh, it's supplying the entire chain! *doh*

I'm clear with that!

I've been know to mess up elementary colors on occasion! I'll double check to see if it's green, but it looks VERY yellow...maybe from old age (not me, the wire)?

No don't splice... Move the wires to a different gauge so only one goes to the spade

As long as all are connected ur gtg

Gotcha! Simple enough!

That Red wire has been replaced. Normally it would be pink from the sending unit. When the pink wire ages, it can look orange. Does the red go to the sending unit or is it spliced somewhere to the one you think is yellow? Does the yellow connect to the center of the sending unit?

Its best not to use a red wire for that because it causes confusion since red is usually +12v supply(unswitched). Once people start "fixing" wiring, they tend to buy a spool of red and a spool of black and thoroughly confuse future owners....I will admit to nothing! ;)

or one spool of red, run two wires and put a piece of black tape on each end of the neg wire

i also will admit to nothing