Gauges Stopped Working Abruptly On the Water

[Bergertime]

Ok.. here I go, back to knowledge well once again...

I was riding home yesterday across the bay and I looked down and 4 gauges were acting weird, 3 (1,2,3 below appeared as if the engine was turned off) but I was traveling at 30 mph.

1) Fuel gauge read empty.. not the case as I put a significant about of gas in on Sat and had only traveled 10 or so miles.

2) Engine volt gauge bottomed out

3) Trim guage bottomed out (Trim worked fine and motor moved up and down while I was on plane).

4) Tach stopped moving and was stuck at 3300 RPM which is where I was cruising at.

-Motor ran fine back to the dock and at home when flushing.  Interestingly, all the gauges worked again parked on the trailer at home.  I suspect this may be a sender or ground issue.  Can anyone suggest where to start looking to eliminate the easy stuff first?

-B

[GoneFission]

You are right - sounds like a ground issue.     Check the main ground connections.  Also see if you have a master plug somewhere that may have worked loose.

[pigbike]

Isn't there some type of large blue connector that causes problems. I read a post on that somewhere. Maybe someone who replaced theirs can give some better info on the location .

[seabob4]

Isn't there some type of large blue connector that causes problems. I read a post on that somewhere. Maybe someone who replaced theirs can give some better info on the location .

Roy,
That would be the main feed for the house systems, not the engine.  House and engine electrics are totally separate on, really, any boat...

Berger,

Assuming you have standard analog gauges, and either an OMC or a Merc, you have 5 wires coming out of the engine harness that power the gauges.  Purple (ignition power), black (ground), tan (engine temp, not normally used), gray (tach sender), and brown (trim sender).  Typically the purple and black are terminated first to the tach, than are daisy chained to the rest of your gauges.  Since they all went dead, the tach is the place to start.  Make sure the nuts on the studs where those wires terminate are tight.

Report back...

[Bergertime]

All,

After checking all the connections the gauges seem to be working fine (except my fuel gage).  I unplugged the gauge at the top of the tank by the wire and it went dead.  Plugged it back in and it only reads a half of a tank at all times.  I even filled the boat up completely this weekend to do some fishing and despite the fuel exited the vent during fill up all she will read is approx. 1/2 of tank by the gauge.

I am thinking that this issue is the unit that reads the fuel level.  Not sure how it works as I have not dug into that yet.  Any pointers as I undertake my next fix-it?  :).  Oh, and a brief explanation on how the fuel level is measured would be greatly appreciated if someone knows or has had a similar experience on a 245 Osprey.

-Bruce

[seabob4]

Bruce,
Fuel systems work the same on all boats that have electric fuel gauges and senders, the 245 is not unique.

Fuel gauges and senders work on resistance.  Yes, the gauge requires 12V, simply because it is an electric gauge.  The sender and gauge work in relation to 33-240 Ohms resistance to ground.  When the tank is empty (float at it's full travel downward), you should around 240 Ohms resistance on a multimeter.  Float all the way up (full)?  Somewhere around 33 Ohms.  One of the reasons we say to check a sender by putting a ground directly to the pink wire is, when you do this, there is no resistance between the 2, hence the gauge instantly pegs full...

[Bergertime]

Thanks for the testing tip, i'll try it over the next day or so.

If I had to replace the sending unit does anyone know what brand and/or model would be the best to use as a replacement for my 245 Osprey. I have looked at a couple at Moeller but they are listed by length.  Will pull mine out and measure but I am hoping for a drop-in replacement that will match the existing mounting holes without having to drill or re-fit the new one.   Has anyone made this replacement before on a 245 Osprey or the like?

Bruce

[seabob4]

WEMA...http://www.wemausa.com/tank-sensors/det ... ensors.htm

Any length you need...

[Blue Agave]

The mounting pattern is standard. Check into a WEMA sender.

[Bergertime]

Thanks for the quick response on this.  Looks like an easy install if the mounting holes are standardized.

B

[seabob4]

Thanks for the quick response on this.  Looks like an easy install if the mounting holes are standardized.

B

Yep.  Pull the old sender, but don't go by it's length.  Stab the tank with a tape measure to get the true depth of the tank from the underside of the sender mounting hole.  Subtract 1/2".  That's the length of the sender you want...

[Bergertime]

As usual.. I can't thank you all enough!!  

I have one follow-up question...  I looked at WEMA and Moeller and the WEMA (recommended) is about twice as much.  Is there a difference b/t the two products that makes the WEMA a smarter purchase?  Visually it looks a little more robust but interested in the groups thoughts.

B

[seabob4]

As usual.. I can't thank you all enough!!  

I have one follow-up question...  I looked at WEMA and Moeller and the WEMA (recommended) is about twice as much.  Is there a difference b/t the two products that makes the WEMA a smarter purchase?  Visually it looks a little more robust but interested in the groups thoughts.

B

Simple answer.  You get what you pay for...

[Bergertime]

"Nuff Said!!"    Thanks  

[seabob4]

"Nuff Said!!"    Thanks  

Kinda figured... 8)