Merc fuel gauge out

[mphsjeep]

Great first boat day yesterday(late start to the season, I know). We have a 98 Stingray 19' with a Merc 3.0.

Was told this is electrical and post here.

Fuel gauge is not working. This has never worked perfectly. The needle would always jump around while in motion but now has went dead. First part of the day the needle stayed around the "E" with minor movement like it was stuck then dropped way below. I have fixed floats on jetskis but this looks more complicated. Is there a float? Are there fuses to check? Ideas?

Thanks in advance...

 

[Don S]

Re: Merc fuel gauge out

Look in the sticky at the top of the page, Item #7 is how to troubleshoot the fuel gauge.

 

[mphsjeep]

Re: Merc fuel gauge out

Sitting in the boat......jumped purple "S" to ground, the needle only jumps up about 1/8" or so. So is that it, replace gauge? Did the jumpy needle mean this thing was on its way out?

Or from the sticky " loss of +12 volts or ground at the gauge. Fix it then retest." What else can I do to fix it besides replace?

 

[Grub54891]

Re: Merc fuel gauge out

Clean all the connection points,even at the guadge,test per the stickys,replace either guadge or sender,wichever is faulty....
Grub

 

[mphsjeep]

Re: Merc fuel gauge out

Give it a shot. Is there a way to independently test the gauge? Thinking directly to a battery?

 

[Bondo]

Re: Merc fuel gauge out

Sitting in the boat......jumped purple "S" to ground, the needle only jumps up about 1/8" or so. So is that it, replace gauge? Did the jumpy needle mean this thing was on its way out?

Or from the sticky " loss of +12 volts or ground at the gauge. Fix it then retest." What else can I do to fix it besides replace?

Ayuh,.... The Sender wire Should be pink, 'n the Power wire should be purple,...

 

[mphsjeep]

Re: Merc fuel gauge out

So bridge purple to ground? Just confirming..........I was thinking to test with a independent battery directly wiried, to bypass the wiring and everything else just to totally confirm its the gauge.

 

[Silvertip]

Re: Merc fuel gauge out

You need to diagnose as directed. If this boat is new to you, the prior owner(s) may have mucked with the wiring so I would be careful about just using wire colors to identify terminals. The gauge has an "S" on the back for "Sender" and an "I" for "Ignition/+12 volts). Ground will have the ground symbol. Use those symbols to identify terminals. If the gauge does not have +12 volts or ground, jumpering the terminals does nothing for you. You need a voltmeter to test for voltage, and an ohm meter to verify the ground. If either of those are missing the gauge will not work. The term "Fix It" means to fix +12 volts and ground which is not a gauge problem. It is a wiring problem. If the gauge has +12 volts and ground and the gauge does not respond with a full scale reading it is sticky or just bad. If it reads full scale when jumpered then you move on to the pink wire and sender tests. No need to reinvent the wheel here.

 

[NYBo]

Re: Merc fuel gauge out

So bridge purple to ground?

NO! If the gauge is wired as per the proper wire colors, that would create a dead short. You would ground the pink wire, again, if the wiring conforms to the color standards.

 

[Don S]

Re: Merc fuel gauge out

Here is a troubleshooting guide from Teleflex that shows the color codes of the wires a bit clearer.

View attachment fuelsender.pdf

 

[mphsjeep]

Re: Merc fuel gauge out

Perfect....I have a green wire coming off my sending unit as well. Will test when get home. Thanks all for being patient with the slow new guy :joyous:

 

[Don S]

Re: Merc fuel gauge out

Check that green wire and see if it goes to the fuel fill. It may be the static ground for the fuel fill.

 

[mphsjeep]

Re: Merc fuel gauge out

Finally got in the boat with a meter....kids will distract you like that. 99% its the gauge. Wiring is stock. Volts from Purple. Resistance from pink. Part ordered and was pleasantly surprised the identical one is still made. Thanks to all for the help with this learning experience!!