View Full Version : Fuel gage system not working

06-10-2005, 07:16 AM
What are steps to check / diagnose the fuel gage not reading anything? Since there are two parts, gage on dash, and sender in tank, I assume I need to check both.

The gage on the dash should have some sort of voltage signal from the sender?

The sender should get power from somewhere & send a signal to the gage?

I haven't dug in too deep yet, but was curious if anyone had tips / suggestions before I do that may help with time. Thanks.

06-10-2005, 09:21 AM
What year is the boat? I have an 01 X-9 and there are known grounding issues with the gauges of boats around that vintage.

06-10-2005, 09:35 AM
Boat is 1994 vintage.

Had to type long answer, apparently there is a 10 charater minumum to posts...

06-10-2005, 09:39 AM
I see you have a 94 205 w/lt1, have have a 190, same year and engine, i recently had the same problem, the guage read full all the time and what happened was the float in the tube inside the tank became swelled and couldn't slide inside the tube. Other problems could be the magnets have fallen off the foam float. To remedy the situation i took the float tube out, pulled the cap off the bottom, and trimmed down my float so it could easily slide up and down the tube. I used a series of utility knifes and saw blades. Then i epoxyed the magnets in place, leaving about a 1/8 inch space between the two. And put everything back together. It now works fine. To test your guage you just need to pull the entire dash panel off and then ground your guage and see if the needle reads completely full, or pegs off the full, this will indicate that the guage is working correctly. Hope this helps.

east tx skier
06-10-2005, 11:04 AM
Like the man said, probably the sending unit. I'd check that first. Replaced mine last year.

Workin' 4 Toys
06-10-2005, 12:26 PM
We had an 86 and a 91 that both needed sending units when gauge acted up.

06-10-2005, 01:28 PM
I would guess it's the sending unit. The guages seldom fail. I believe the wiring is pretty standard and if you disconnect the power wire from the sending unit (pink), turn on the key and then touch the wire to the ground connection it should peg the guage. Don't hold it on there for long, all you need to see is the guage jump up and you know it works. It it does then you have a sending unit problem and likely the fix suggested above will get you on your way.


06-10-2005, 02:34 PM
Nate, how did you remove the bottom cap from the sending unit. looks glued together on mine. my 94 always read full. I pulled the sending unit out last night and opened up the top vent hole and the bottom drain hole w/ a slightly larger dia drill bit. I think it was not draining and sort of suffering from vapor/hydraulic lock?
the float moved freely inside the tube w/o gas in it. I tested it as I inserted it back into the tank w/ the key on, it was moving the gauge up and down. real test as soon as the wind dies down around here, 25 mph and whitecapping today!

06-10-2005, 03:18 PM
mine just fell off, i guess the glue weakened up over time. On other boats i've had to pry them open after working the edges with a razor blade or knife.

But if your float moves up and down freely then you should be good to go.

lakes Rick
06-10-2005, 09:09 PM
Remember the magnets also fall off on this type....

I replaced mine with one of the factory "electric" sending units... These are the replacement for the old float and magnet type originally used.. I should say they were the replacement back in 99, and I assume they still are...... Mine works great and I would encourage this type of replacement ... Just my opinion.....

06-16-2005, 08:07 AM
Thanks for the help, I unfortunately haven't had the boat uncovered to check yet, due to weather, travelling for work, and being too busy.

03-18-2006, 06:33 PM
My 91 Prostar fuel gauge is jumping around. I troubleshot it down to the fuel sending unit. Skidim wants about $73 for it. Is there anywhere else I can order it from?

03-18-2006, 07:59 PM
My 91 Prostar fuel gauge is jumping around. I troubleshot it down to the fuel sending unit. Skidim wants about $73 for it. Is there anywhere else I can order it from?

You probably won't do better than SKIDIM, but ask your dealer the cost to replace and or the price of a sending for a DIY project.

Replaced mine about 3 years ago on our '89 ps and it took all of 45 minutes!

03-18-2006, 08:00 PM
SKIDIM has 10% off right now....atleast that is what someone posted on here...

03-18-2006, 08:29 PM
You probably won't do better than SKIDIM, but ask your dealer the cost to replace and or the price of a sending for a DIY project.

Replaced mine about 3 years ago on our '89 ps and it took all of 45 minutes!

Go straight to isspro, they are $65 for an OEM replacement. Waterski-Marcoisland also recommended a company in florida who is producing stainless steel versions for $55... I agree, skidim is a little over priced on this item!

03-18-2006, 09:04 PM
Most likely the gauge- if/when you take it apart, use a file that is about the same thickness as the groove, but run it through there to embiggen it. The floats frequently swell when reformulated gas is used.

92 190 PS
04-13-2006, 01:46 PM
Was going to try to sand mine down like many have mentioned on the board. As I pulled off the float inside the tube one of the magnets took off. What purpose do the magnets serve?

04-13-2006, 02:18 PM
When a magnet is in close proximity to an energized circuit, it will affect the circuit. You need both for the sender to work properly. If you find the magnet, you can use SuperGlue to hold it in place.

92 190 PS
04-13-2006, 02:24 PM
Thanks Jim. One last question I think. Where do these magnets go? Are they glued to the top of the float?

04-13-2006, 02:28 PM
There should be two small slots in the float. IIRC, they were at the bottom, but I haven't disassembled that kind of sender in a while. If your sender bottom is held in with screws, you could try it in one orientation and if it never shows full when tipped over, you can reverse the float.

04-13-2006, 03:43 PM
Some pics of this process sure would be useful next time someone is pulling theirs apart.

92 190 PS
04-13-2006, 04:09 PM
I'll post the pictures of mine in pieces tonight. Just not completely sure how to get magnets back together at this point. I'll take a stab at it tonight and test it to see how it goes.

92 190 PS
04-14-2006, 08:03 AM
Put the gas tank back together and forgot to get pictures. I'll get them when I put the new one in... The quick fix didn't work out so well. The sender is working a bit, but doesn't go all the way to full. When I get an extra $70 laying aorund I'll replace it...

04-14-2006, 09:23 AM
I just have replaced mine on my 93 PS190.
Ordered it from skidim cost 75$ and works perfectly.
With this gauge, you can adjust the empty and full level...

04-14-2006, 09:29 AM
92- turn the float around so the magnets are at the top. It's also possible that if the magnets aren't oriented correctly, the fields won't affect the sensor as much as it should.

04-14-2006, 12:39 PM
Boat is 1994 vintage.

Had to type long answer, apparently there is a 10 charater minumum to posts...

My 1994 225 had a similar issue… Over time the bottom of the tube came apart, and the magnets out of the float fell out. I was able to retrieve all parts from the tank, glue the magnets back into place. Then plastic weld the bottom of the tube back on using a soldering iron.

92 190 PS
04-14-2006, 12:42 PM
Thanks Jim I'll give that try. If all else fails, the float works now and at least moves to empty. It could be worse. If I do pull it out again to switch the magnets I'll get some pictures for everyone's benefit.

04-14-2006, 08:05 PM
I would buy a new sending unit. I just replaced mine on a 94' Maristar. The new unit is improved over the old float units. It was relatively cheap and took ten minutes to replace. Problem solved! The new unit has high and low adjustments on the sender. Good Luck

04-14-2006, 08:10 PM
A quick easy check would be to make sure that the gauge is grounded behind the dash.

My grounding wire came off last year, and the gauge wouldn't function properly.

92 190 PS
04-20-2006, 03:07 PM
Looking for a second opinion to be sure I'm ordering the correct parts. Replacing the float in my 92 PS 190 and it looks like there are two different models to choose from, depending on if I go with DIM or ISSPRO.


Anyone had any expierence with either? Looks like the ISSPRO is more like the one I'm taking out...

east tx skier
04-20-2006, 03:15 PM
The one from DIM is similarly priced to the ugraded unit I bought from a MC dealer to replace the failed unit in my 93 205.

If it helps, the MC part number is 153260. I paid $75.61 (tax included).

Looking at the skidim listing, it shows the same part number, but questions 91/92? I figured it'd be the same, but now I don't know.

92 190 PS
04-20-2006, 03:21 PM
My hesitation is the same as yours. If all else fails I'll give the folks at DIM a call and have them verify the model before I order it. Willing to give DIM the extra $10 if it's the right part. Thanks for the udpate.

east tx skier
04-20-2006, 03:31 PM
Well, to clarify. That was the right part on my boat (although DIM wasn't selling it back then).

92 190 PS
04-27-2006, 01:47 PM
Ordered the new one from DIM the other day....

Here is the first (the float)..I'll post a couple more in a sec...

92 190 PS
04-27-2006, 01:50 PM
This is from the top of the fuel sender...

92 190 PS
04-27-2006, 01:54 PM
One more of the sending unit itself..

92 190 PS
04-27-2006, 01:56 PM
Here you go with the last one.

05-23-2006, 08:43 AM
Are you pulling the tank to pull the sending unit or is there a way of pulling the sending unit without pulling the tank?

92 190 PS
05-23-2006, 08:51 AM
I had to pull the tank to get to it. The sender is about a foot long and I don't think it would have come out of the top of the tank without pulling the tank out. My tank was very easy to slide out (just 8 screws on 4 brackets)...

Not sure if you're working on this project, but if you are I purchased the sender below and it worked perfectly. Simple adjustments on the top and installed in same manner as previous sender...


05-23-2006, 09:52 PM
My guage is showing empty and I have pulled the wires and crossed them to peg the guage. So it sounds like I need a new sender. I have a full tank in the boat so I am going to wait until it gets lower to remove the tank and replace the sender. Thanks for the info.