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Gas tank fuel gauge stuck on my 1990 33 foot Tiara

C

contender31

Regular Contributor
Hello again - this weekend I embarrassly ran out of gas. Before I left the dock my instrument panel gauge showed half full, not trusting that gauge I looked at the gauge on top of the tank - it read the same - 1/2 full. Has anyone experienced this and what is the fix? It appears the gauge on the instrument panel gets its signal from the tank gauge which of course is stuck or broken.

Any ideas or experiences?

Thanks in advance
 
Mine have never worked right (1985 twin 454's) so I always go off the hour meter. Since you are always using 1/3's (1/3 out 1/3 back and 1/3 in reserve) I have found you can easily calculate average fuel burn and be within 5 gallons. on a 100 gallon tank per engine thats not a bad calculation. After two or three stops at the fuel dock on different runs....you will find a pretty average fuel burn. Or....can you run a wooden stick down the fuel fill cap? Square tank and a stick you can get a measure right to the gallon.
 
035760-10_07168-72dpi.jpgYour gauge sounds like a capsule type. The capsule is held on by two screws to the top of the in tank unit. It is easily replaced. It uses a magnetic connection to the in tank float. You do not disturb the gasket between the sender and the tank at all.
 
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northern_lights said:
.................. Or....can you run a wooden stick down the fuel fill cap? Square tank and a stick you can get a measure right to the gallon.
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Wish that I could but I have an anti-siphon gizmo in the neck of the filler lines for each tank.

I think I could guess how much gas is in each tank by looking at the reflection of my Bar-B-Q lighter if I held it over the open tank but I think I might not have time to tell anyone what my 'guess' was.View attachment 1101 ;););)
 
Think I'd figure out the source of the problem and then fix it if you want the gauge(s) to work. My initial stab is that the float is bound and needs to be replaced with a new sender, as you also suspect. Pull the wire off at the sender and see if the gauge drops back to E with the key on. if it does, momentarily ground the sender wire while somebody watches the gauge; if it jumps to F the gauge is fine.

Another key piece of info is the answer to "how much fuel went into the tank?"
 
Yes that is what the sender looks like - except my needle is red in color - I am going to do the test recommended and see if it is the sender. Both gauges show the same so my guess is it is the sender. If it is where canone buy one? I live in south florida

Thanks appreciate the feedback
 
BOW has these in a couple of flavors. They do break electrically, often. ANd, the two little screws weld themselves in, and shear upon removal attempt. You can use RTV to stick the new capsule in. yes, I hate this system. If at all possible, buy Ispro senders.
 
lmao - no sooner do I go out and try to take out the little screws, i come back and read they break off. Thats exactly what happened - a man with experience you are:):)
 
no rocket science here. any 6/32 screw below the deck into aluminum will shear. One thing i have NOT figured out is how to put in the little faces in the message!
 
the gauge I have on the tank is a Rochester and the instrument gauge is a VDO - they sell the Rochester gauge at bow or does it matter what brand Iuse?

Thanks that last post was for you
 
Be aware there are electrical varieties of fuel senders. (and other senders too). Most domestic stuff uses 240 ohm full/ 33 ohm empty. VDO sells that AND the euro variation. NOT compatible.

correction; 240 empty/33 ohms full
 
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sorry; full=33; MT= 240ohms. The euro is full=0, MT=90. If you shorted the sender wire to ground and the gauge read full, then you have the US style.
 
diver_dave said:
sorry; full=33; MT= 240ohms. The euro is full=0, MT=90. If you shorted the sender wire to ground and the gauge read full, then you have the US style.
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I got the gauge off the tank and it had alot of salt corrosion between the gauge and the contact. I cleaned it off and re installed it and no change. I think the gauge is bad. The gauge at the helm will drop to E when I turn on the key and disconnect the wire leads an do nothing when grounded as explained.
 
Yeah, watch those 1/4" push on terminals. corrosion can cause issues there. Notice when you pull the connector off, there is only a fine line of shiny metal on the tab? I was on a 31 Tiara recently, and dealt with this very issue. Capsule was bad, and the connections I was able to use fine sandpaper and De-Oxit on with success. If you can get hold of a 100ohm fixed resistor (radio shack), that is a good gauge test. It reads half scale if good.
 
thanks when i pulled the connectors apart they did not seem to have any what I would consider to be corrosion that would interfere with a good contact but the female end did have a fair amount of corrosion on the top.
 
New gauge and no reading at all at the tank??? the terminal connectors should have nothing to do witht the reaidng at the tank gauge should it? the gauge is magnetic, all the contact terminal wires that connect to the gauge do is send the reading back to the helm doesn't it?
 
contender31 said:
New gauge and no reading at all at the tank??? the terminal connectors should have nothing to do witht the reaidng at the tank gauge should it? the gauge is magnetic, all the contact terminal wires that connect to the gauge do is send the reading back to the helm doesn't it?
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The SENDER is magnetic. I'm calling the gauge the meter at the dash. But, yes, the mechancal part of the sender does have a little dial, and it should work without any power. There is a magnetic transfer, as you say. It is also possible the interior part of the sender is stuck/defective. Have you looked at these yet? http://www.isspro.com/products.php?cat=99
 
I did check out the site isspro and it looks like a better design but Tiara engineers in there unfriendly design made the unit difficult to service and access. The unit is 1/2 way into the leadiung edge if the drain channel of the deck lid. Typical engineering blunder - greagt in concept poor in servicability:mad:
 
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