gauges

[amoreau]

Has anyone found a solution to the moisture that collects inside the gauges at the helm. It happens mainly when the engine is running.  I thought about loading up the inside of the gauge compartment with (silicate packs?) to dry everything out.  I thought I read about using a hair dryer in back of the gauges also.  Any thoughts?

[kellyday]

I to am experiencing fuel gauge failure with my 97 catalina 34MkII. I have narrowed it down to the sending unit.However, I am wondering how do I go about replacing the sending unit when it is not accessbile. I removed the port side panel in the rear compartment in an effort to slide out the fuel tank but found this is not possible because of lack of clearance. The access cover in the rear lazerette allows accessibility to the fuel shut off valve but not quite to the sending unit.The only thing I can see to do is cut a hole through the bottom of the lazerette above the sending unit and remove it this way and then install another access cover to plug the hole.Does anyone have a better suggestion as I am reluctant to cut a hole in the compartment.

[kmorton16@comcast.net]

Kelly,  We also have a MKII, and plan to cut an 8" hole to remove the gage.  An 8" port will be added to replace the smaller one.  Ken Trident -1300

[Stu Jackson]

Fuel Gauge

A reference source:  http://c34.infopop.cc/6/ubb.x?a=tpc&s=329609511&f=829605811&m=232609811&r=432609811#432609811

For foggy meters, just turn your running lights on, they are usually connected to your instrument lights, or at least they should be, unless you use flashilgihts.

Stu

[rab1090]

I own a 1996 Catalina 34 MkII (#1304) and have just experienced what appears to be a failure of the fuel sending unit.  I'm curious as to the outcome of others in replacing the sending unit.  As access to this unit appears to be a problem, have there been successful
replacements on the MkII models?

[Mike and Theresa Vaccaro]

Bob,

Your sending unit has a ground wire.  Before removing the sender (which are fairly bulletproof), be sure to trace the ground connection.  Check it at the sender and wherever it terminates.  On our boat, a 1988, this wire terminated at the engine.  A call to the factory may provide a clue about color and terminus.  

Once you've got the wires sorted, clean all the connectors and properly reconnect to bare metal, and then check the gauge.  

95% of all electrical gremlins are the result of ground problems--especially on boats where corrosion and vibration are often an issue.

Good luck!

Mike

P.S.  If you're willing to spend the extra money, sealed instruments are available that don't fog up.  Most standard instruments fog up and the internal light (wired to the key as Ron states!) will come on when the key is ON, eventually drying them out.  All of the stock Seaward panels installed at the factory use standard, i.e., non-sealed instruments.

[Mike and Theresa Vaccaro]

I actually stand by my "bullet proof" statement with the "it depends" caveat!  

A resistive type sender unit tends to be highly reliable, although it has one moving part (the float arm).  In many cases, they tend to work longer, better than (much) more expensive capacitance type senders (no moving parts, but dependent upon proper calibration, installation and maintenance).  Resistive senders can be extremely accurate when combined with a "smart" fuel guage, even in an assymetrically shaped tank.

None of this is necessary in a sailboat that burns only about a 1/2 gallon per hour!  A fuel gauge is almost engineering overkill...A watch (or hour meter on the engine) and accurate log can be a suitable substitute for the gauge.

My real point was to fix the easiest thing first, especially if it's the most likely culprit.  If you replace the sender without testing it or shooting the wiring (first the ground from the sender itself, then the wiring at the engine control panel in the cockpit), you may end up replacing a sender needlessly.

'Course it's entirely possible that the sender has failed!  But you can test it with an ohm meter to find out for sure.  To do this, you set the meter up to read resistance, and connect the positive lead to the guage output and negative lead to the ground. Different manufacturers use different logic (e.g., low ohms at empty, high ohms at full OR visa versa).  But if you move the float arm and resistance changes as the arm moves, the sender is probably O.K.

Some examples for different sender manufacturers are:  

Stewart Warner fuel senders are: Empty - 220 to 260 ohms; 1/2 tank - 80 to 120 ohms; full tank -20 to 50 ohms. This is normally noted as 240 ohms at empty and 33 ohms at full.

GMAC fuel tank sender will read in the opposite direction. At empty, it will read zero ohms and at full it will read 90 ohms.

Ford/Chrysler fuel tank sender will read zero ohms at empty and 73 ohms at full.

Perhaps someone on the message board has the specific figures for the senders that Catalina uses.  

Cheers,

Mike (embarassed graduate of the "Learn everything the hard way first" school of maintenance!)

[Ted Pounds]

In Mainsheet a few years back one of the Tech Notes sections (I think it was C36) had a fuel guage troubleshooting procedure.  It was very easy and I used it to determine I needed a new sender.  I went back and looked for it, but I couldn't find it.  Maybe someone else remembers it and can dig it out?

Ted