New gauge readings

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  • team118
    Senior Member
    • Feb 2009
    • 40

    New gauge readings

    Hey guys!

    I have a quick question. I installed new oil preussure, water temp, voltmeter and fuel gauges on my Catalina 30.

    I started the engine this past weekend using a 5 gallon bucket of water. I noticed that the fuel gauge and voltmeter were working, but the temp and pressure gauges were both pegged.

    Is this normal when starting up, I don't remember as I just bought the boat last September. The gauges ran normal the few times I used the motor before pulling her out for the winter.

    I replaced the gauges and sending units with new Stewart Warner gauges from Moyer as an FYI.

    Am I missing something or they settle down to their normal operating range once the engine warms up. Obviously, only 5 gallons of water isn't a lot of time. But it seems to me that when I start my car the oil pressure goes right to normal the temp gauge creeps up from cold to normal in a few seconds and this should be how the boat gauges should act.

    Thanks
    Chris
  • sastanley
    Afourian MVP
    • Sep 2008
    • 6986

    #2
    Chris, I think that usually indicates a ground problem on the gauge. I would try a jumper wire to the ground on the affected gauge(s) to a known good ground source first. If the gauges are grouped together, they probably have a common ground anyway

    Once you get them working, take some pics! - I have a Catalina 30 and plan to replace most of the gauges as well, someday.
    -Shawn
    "Holiday" - '89 Alura 35 #109
    "Twice Around" - '77 C-30, #511 with original A-4 & MMI manifold - SOLD! (no longer a two boat owner!!)
    sigpic

    Comment

    • High Hopes
      Afourian MVP
      • Feb 2008
      • 530

      #3
      Hello chris,

      You're missing the gauge grounds or you have open transducer circuits. The gauges should read accurately within seconds of turning on the ignition switch. The drawing below may help.

      Steve
      Attached Files

      Comment

      • team118
        Senior Member
        • Feb 2009
        • 40

        #4
        rats...

        I think you guys are right. My original setup was for an ammeter in the panel, but Stu Jackson from the Catalina forums convinced me this was a dangerous setup, so I pulled it and put in a voltmeter.

        The voltmeter works, but I must not have hooked the grounds from the other 2 gauges back up correctly. The fuel gauge works because the ground from the tank goes directly to a NDP...

        Darn panel is siliconed back in place...for the second time! Oh well.



        I ordered the panel using some nice software that cut the holes and engraved it. I saw it in Sail Magazine, Front Panel Design in Seattle, WA. Still need to clean up the excess silicone.

        Fair prices and fast service. I used the original engine pod, I'm going to sand it and repaint next year and it should look brand new!

        Thanks for the input, and I guess I'm pulling the panel....again.
        Chris

        Comment

        • 67c&ccorv
          Afourian MVP
          • Dec 2008
          • 1559

          #5
          Nice looking panel you got there dude!

          What was the reason for the change from ampmeter to voltmeter? Curious about what the "danger" is?

          Comment

          • High Hopes
            Afourian MVP
            • Feb 2008
            • 530

            #6
            Chris,

            Awesome panel!

            You may want ot test your gauge panel before you glue it back in.

            I'm not sure I'd call an ammeter dangerous. But everyone has switched to just voltmeters, so I went with the flow, too.

            Steve
            Last edited by High Hopes; 05-14-2009, 09:35 PM.

            Comment

            • rigspelt
              Afourian MVP
              • May 2008
              • 1186

              #7
              Originally posted by 67c&ccorv View Post
              What was the reason for the change from ampmeter to voltmeter? Curious about what the "danger" is?
              [Not a mechanic or engineer, just an amateur boater.]

              I wondered about this too. Our old boat and many like it apparently went decades with that long heavy wire run to an ammeter at the cockpit ignition panel, branching back forward with two heavy wires, one for house and one for engine, including recharging for the battery (alternator output runs all the way aft to the ammeter in the ignition panel, then forward again to the engine and battery).

              I was just reading about this issue on an auto forum a few days ago, where I got the sense that in the auto world they also may have shifted from that kind of ammeter wiring to voltmeters and much shorter main distribution wires for engine and "house" circuits.

              Some disadvantages of ignition panel ammeters, according to my reading using Google:
              - Increased risk of shorts causing fires over those longer wire runs in vehicles (I have no idea how big a risk this is).
              - Increased distance and number of connections and therefore risk of poor connections degrading alternator output to the battery and other electronics.
              - Ammeter reads zero if the alternator has failed and is not charging, and if everything is working but the net current flow happens to be zero.

              Some reading that may be of interest (random finds with Google, cannot vouch for validity):




              My new wiring has an 8" run of cable from the alternator to the Batt post on the solenoid, replacing the original 16 foot round trip run of heavy wires. Now I have a simpler voltmeter in the panel that tells me if the engine circuit has too little or too much voltage, there is less current draw aft to the ignition panel, and we have separate engine and house circuits. This design does not, however, eliminate the need for a 16' round trip for power from the Batt terminal of the solenoid to the ignition key in the cockpit and back to the engine via the purple ignition ciruit. It only shortens that run for the house supply, and the battery recharge from the alternator.
              1974 C&C 27

              Comment

              • Administrator
                MMI Webmaster
                • Oct 2004
                • 2166

                #8
                I ordered the panel using some nice software that cut the holes and engraved it. I saw it in Sail Magazine, Front Panel Design in Seattle, WA.
                That panel is really something! Great find!

                Here's the link to the company.

                Bill

                Comment

                • High Hopes
                  Afourian MVP
                  • Feb 2008
                  • 530

                  #9
                  Dear "Not a mechanic or engineer, just an amateur boater,"

                  I read your last message carefully and I think you may benefit, if may be so bold, from a few tips. Therefore, with best intents forward, here are a few concepts that may allay your concerns.

                  (1) Signaling and Power Devices: Electricity can be used to transport power or it can be used to transmit signals.

                  There is no electrical "power" needed for the A-4, except for the starter motor. By power, I mean many Watts (Volts x Amps). The ignition coil draws a few amps and the gauge lamps draw, maybe, 1/3 amp each. With a crank start, the A-4 would run just fine off eight flashlight D cells and a tiny alternator.

                  Signaling devices use electrical currents to encode information. Operationally, all of the gauges on our boats are identical internally. Only the sending units and the scales are different. There is negligible power associated with signaling devices as the intent is to use only as much power as needed to provide the information (temperature, pressure, fuel, depth, etc.).

                  There are two items on the engine that are somewhere in between a signaling device and a power device. A solenoid can be thought of as a power device in that it works a bendix and switch. This requires mechanical energy. But, it is also a signaling device in that it signals the starter motor, a power device, to do work.

                  An ammeter is a signaling device as it provides information. But the curious thing about it, is that it has to carry the power it is measuring to be able to measure it. It, itself, consumes little power.

                  So. . .

                  Tip: Do not worry about the solenoid power. It draws 1/10 of the power that the starter motor requires. If the battery can power the starter motor, it will certainly power the solenoid. With the starter motor running and drawing 120 amps, the solenoid is just a signaling device. The rating of a wire is spec’d at continuous use. Solenoids circuits do not have time to get hot. Your starter motor will chew your battery up before that can happen. This is not a critical item.

                  Tip: An ammeter, although a signaling device, still requires power rated wiring as it carries the alternator charging currents that will recharge the battery. Installing an ammeter introduces additional expenses for heavier circuit wiring than that needed for a voltmeter. This is why they are being abandoned. You decide.

                  Tip: Do not worry about the wire run length too much. Other than beefy wires for the starter motor, none of the runs on your boat, even up and down a mast, will introduce more than 1/10 of an ohm. Copper wire is a VERY good conductor.


                  (2) Battery Resistance: Batteries do not lose volts; the just develop resistance. Charging a battery takes resistance out of the battery (it’s a chemistry thing).

                  In high current circuits, the circuit resistance is low. Internal battery resistance becomes a problem when the load that it is trying to service has a resistance on par with the battery. When the internal battery resistance and the external battery resistances are equal, output voltage at the battery terminals is halved. “Inside” the wet cells are still operating at 2 volts each (it’s a physics thing). This is why a GPS and VHF Radio work fine even when the battery “doesn’t have enough juice” to turn the engine over. The GPS and VHF Radio get 12 volts, the starter sees six.

                  Tip: Putting unequally charged batteries in parallel and charging them together is a fine idea. The weak battery will not draw down the stronger battery. The weaker the weaker battery, the higher its internal resistance, and the less current it can draw (or “take in”). It therefore cannot steal much power from the alternator away from the good battery. Don't be afraid to use the BOTH position on the battery switch or install an ACR.

                  Tip: On my boat, things like the UHF radio and GPS had grossly overrated fuses. The radio draws 2-3 amps in transmit mode, but uses a ten amp fuse. I cannot draw more than three amps with the GPS at full screen brightness, yet it uses a 7-amp fuse. Navigation lamps were drawing less than six amps, and a 15-amp fuse was installed. Do not make the mistake I did of using the fuse size as an indicator of device current requirements. Use appropriately sized fuses for actual current loads. Keep low power devices at low power. Any excess current draw above nominal conditions is making something hot – a no no.

                  Hindsight: If I had it do it all over again, I would have bought a one spool of #14 wire and used it for every circuit except the starter motor circuit. In my calculations, I could not find any other significant “power” device on the boat. Next to the starter circuit (120 amps), the highest rated circuit I found was for the cabin lamps (12 amps). Now where did I put those D cells?

                  Cheers!

                  Steve
                  Last edited by High Hopes; 05-15-2009, 03:13 PM. Reason: typos

                  Comment

                  • Dave Neptune
                    Afourian MVP, Professor Emeritus
                    • Jan 2007
                    • 5046

                    #10
                    Gages

                    team 118, I have run into a similar situation trouble shooting around the marina or boat yard many times. Most marine gages are supplied with a ground wire. A lot of automotive type gages are supplied without a ground wire as they are grounded via the mounting bracket itself, ie the gage is the ground connection so you may need to ground the gage. I have also seen the lighting supplied with a ground wire and/or grounded through the mount. The lighting is usually a separate connection to accomodate dimming the light.

                    Nice panel BTW

                    Hope this may be of some help.
                    Dave Neptune 1970 E-35MkII original A-4 still ticking

                    Comment

                    • team118
                      Senior Member
                      • Feb 2009
                      • 40

                      #11
                      Some great help

                      Thanks guys.

                      The reason I changed the ammeter was because I have read a lot of literature about running so many amps through the ammeter and back again through a 10awg wire. Rather than beef the wire up, I changed out to a voltmeter.

                      I'll run the ammeter closer the battery another day.

                      I think it may be the ground from the harness. Before with the ammter was installed, there is a grounding wire from the harness to the gauge. Now it runs from the voltmeter and is bolted to the engine.

                      The rest of the grounds rund to a dedicated negative bus and then to the engine.

                      Would this have an effect on the gauges?

                      Comment

                      • MikeB.330
                        Senior Member
                        • Jun 2006
                        • 246

                        #12
                        you could always use a Link 10 or some other battery monitor that uses a shunt. doing so would avoid having to run large cable to the gauge. With this type of system you are not running any current through the gauge itself.

                        Xantrex power products provide reliable power safely and efficiently, perfect for RVs, marine environments, commercial vehicles & more.



                        and the one newmar sells.


                        and the manual for the Nemar DCE


                        Mike
                        Last edited by MikeB.330; 05-17-2009, 06:56 PM.

                        Comment

                        • team118
                          Senior Member
                          • Feb 2009
                          • 40

                          #13
                          Still no dice....

                          The boat was launched yesterday.

                          The gauges are still pegged with the exception of the Fuel Gauge and the Voltmeter.

                          I ran a jumper from the Oil Pressure gauge ground directly to the battery and it still remained pegged. Both the Oil and Water Temp gauges are brand new along with their sensors.

                          I have a thought thought. The Fuel Gauge housing is plastic, the other guages are metal.

                          The new panel is made of aluminum. Would this effect the gauges no matter how I ground them? This is driving me crazy.

                          Comment

                          • 67c&ccorv
                            Afourian MVP
                            • Dec 2008
                            • 1559

                            #14
                            Originally posted by team118 View Post
                            The boat was launched yesterday.

                            The gauges are still pegged with the exception of the Fuel Gauge and the Voltmeter.

                            I ran a jumper from the Oil Pressure gauge ground directly to the battery and it still remained pegged. Both the Oil and Water Temp gauges are brand new along with their sensors.

                            I have a thought thought. The Fuel Gauge housing is plastic, the other guages are metal.

                            The new panel is made of aluminum. Would this effect the gauges no matter how I ground them? This is driving me crazy.
                            When you replaced the sending units on the engine what did you use to seal the threads?

                            I would suggest checking the resistance of the sending unit housing to engine block to if you have used a sealant that insulates the unit from the block.
                            Last edited by 67c&ccorv; 05-27-2009, 10:06 PM.

                            Comment

                            • High Hopes
                              Afourian MVP
                              • Feb 2008
                              • 530

                              #15
                              Take the gauge sending wire off the sending unit. Ground the sending wire to the engine block, off and on. This should make the gauge pointer flick back and forth. If it doesn't, the wiring is wrong. If it does, then your sending unit has a problem.
                              Last edited by High Hopes; 05-28-2009, 12:13 AM. Reason: oopsy

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