trim gauge

[Fernand Fluet]

recently add trim gauge but needle always at the top like new in boxes. moved sender nothing happens.How can I know if my sender or my gauge are good or bad.
Is the sender simply a resistor? I have checked the wiring looks good.

 

[Boatin Bob]

Re: trim gauge

What kind of motor? I/O or outboard and which brand? The sender is a variable resistor and must match the same resistance range of the gauge. Have a look at this link for some more info on Trim Gauges/Senders and scroll down in the middle section until you come to Trim Gauges Teleflex Trim Gauge Info

 

[swist]

Re: trim gauge

Not only are the resistance ranges of the various manufacturers' senders different, they don't even all move in the same direction (i.e., on one brand low resistance is max up, and on another brand low resistance is max down). The Teleflex site has a table that tells all.

 

[Fernand Fluet]

Re: trim gauge

Thanks for your help, with your info my sender was the prob,I am new in boating, I would like an explanation of the difference in using the trim swich and the trailer switch, my trottle handle has switches on left side and switches on right side. I am using the ones on the right side. Also my gaz gauge jumps up and down about a quater is this normal when on water could it be the little
rocking of the boat.
Engine is Mercruser 3.0 liter Alpha One

 

[Boatin Bob]

Re: trim gauge

The trailer switch is normally only used when trailering, this allows you to tilt the outdrive all the way up so it won't hit anything while on the trailer, can also be used when beaching the boat but it's normally only used when the engine is off. The trim switch is used while running and there is a trim limit switch on the outdrive to limit the amount of movement so you don't go beyond the safe operating range for the drive and put too much stress on the u-joints and shaft. Boat gas gauges are notorious for not being very accurate as they are just a float that bounces around inside an irregular shaped tank. You may also have a float assembly (fuel sender) that is starting to go bad (I think just about everyone has changed theirs at one time or another). Go to that same Teleflex link I gave above and read the section on fuel senders.

 

[sleepinin]

Re: trim gauge

Fernand,
I heard a trick along time ago, I can't remember where. Anyway, run your tank empty or pump it empty and then go to the gas station and put in 5 gallons and use fingernail polish and put a mark on the gas gauge, put in another 5 gallons and put another mark, repeat this until full. Now your guage will tell you how many gallons you have instead of 1/4,1/2,/3/4, full. And yes your gauge will move quite a bit from the fuel sloshing around and also based on how level your boat is. Cars used to do this pretty noticably also, but they don't seem to do it as much these days, I don't know what they did different with the cars?

 

[Silvertip]

Re: trim gauge

Where the gauge reads will depend on its attitude in the water so marking it in gallons has little advantage over the regular markings. The best thing to do is calibrate the gauge so it reads empty when the tank is empty at its normal attitude (either at the dock or under way). You simply can't make it accurate at all points on the gauge unless you have a tall slender tank which no boats I know of have. Most are long, shallow, and wide which makes it really hard to get an accurate reading.