-
Anyone thought about adding an electronics section??
I have a red wire to the sender at the tank wired to a toggle switch (I am assuming the toggle switch is for reading dual tanks which I have)
http://www.yumaduners.com/albums/alb..._003.sized.jpg
I have a red wire from the gauge (sender post on the gauge) that is not connected to anything right now (when I turn the key on it has 12 Volts thru it)
http://www.yumaduners.com/albums/alb..._001.sized.jpg
I don't do much with fuel gauges soooooo my question now is Before I blow this thing up and have to start over....Do I really want to send 12 volts to the sending unit at the tank??
Thanks,
-
The sender in the tank uses a ground and a resistor to let the gauge know where the float is.
You should only have 12 volts to the 12+ post on the gauge...not the sender post.
-
The sender in the tank uses a ground and a resistor to let the gauge know where the float is.
I figured the sending unit in the tank had a resistor when I looked at them last...I had the sending units out of the tanks to replace the gaskets and both seemed to have Ohm resistance thru some of the float movement.
You should only have 12 volts to the 12+ post on the gauge...not the sender post.
I have 12 volts to the 12+ post on the gauge with a good ground. The sender post has no power,nothing untill I turn the key on...(When I turn the key on I get 12+ volts thru the sender post(must be shorting inside the gauge?) Also with key off I get an Ohm reading of 213.9 when I check across the 12+ and the S post.
-
I have 12 volts to the 12+ post on the gauge with a good ground. The sender post has no power,nothing untill I turn the key on...(When I turn the key on I get 12+ volts thru the sender post(must be shorting inside the gauge?) Also with key off I get an Ohm reading of 213.9 when I check across the 12+ and the S post.
I've never put a ohmmeter on the sending post...so I'm not sure what is normal.
I'd try grounding the sender post and see if the gauge pegs?
-
If you intend to use the switch heres how they should connect. Looking at your pics the red wire from the sender should go to one of the end tangs on the switch. The red wire from the opposite tank to the other end tang on the switch. The center tang of the switch should connect to the "S" terminal of the guage. providing the switch has three tangs (SPDT) single pole double throw.
The black wires from both tanks should be well grounded.
DO NOT CONNECT POWER TO THE SENDERS or the tank !
With everything connected there may be some passive voltage present through the guage at the sender depending on the level of the float (ammount of fuel). If you disconnect the sender wires and the tank ground wire the resistance of the sender should range from arround 300 Ohm to 30 Ohm + / - if you read no resistance then the circut is open and the sender is more than likely bad.
Hope this helps.
C.T. :wink:
-
If you have a ground wire from the sender to the engine/ battery (grounding thru the sender), you'll have 12 volts at the sender. The quick and dirty way to test is to ground the wire at the sender and watch the gauge. If it pegs, then ground the sender, turn the key on and see if the gauge registers. Don't assume the sender's at fault until you've verified it's properly grounded.
-
Cheap Thrills If you intend to use the switch heres how they should connect. Looking at your pics the red wire from the sender should go to one of the end tangs on the switch. The red wire from the opposite tank to the other end tang on the switch. The center tang of the switch should connect to the "S" terminal of the guage. providing the switch has three tangs (SPDT) single pole double throw.
The black wires from both tanks should be well grounded.
DO NOT CONNECT POWER TO THE SENDERS or the tank !
With everything connected there may be some passive voltage present through the guage at the sender depending on the level of the float (ammount of fuel).
When I turn the key on the fuel gauge "S" terminal sender wire has 12 volts thru it...If I connect it to a switch oposite the red wire to the fuel tank sender...With the switch on (12 volts thru the switch) it would be the same as conection straight to the fuel tank sending unit...Right? If you have a ground wire from the sender to the engine/ battery (grounding thru the sender), you'll have 12 volts at the sender. The quick and dirty way to test is to ground the wire at the sender and watch the gauge. If it pegs, then ground the sender, turn the key on and see if the gauge registers. Don't assume the sender's at fault until you've verified it's properly grounded.
I have read this 6 times now and it still confuses me some :rolleyes:
If I ground the fuel tank sender (good ground straight to the battery) and run the red wire from the gauge sender pole, Which has 12 volts when the key is on,to the + side of the fuel tank sender...I should get a reading??
The tank having a resistor at the tank sending unit? 12 volts should be ok if it drops/resists the voltage at the sender?? I have no voltage to the sender at the tank as of now (the + red wire from the tank sender goes to a switch and that is it.)
I am mainly looking to use one sender from one tank and get a reading....then I will go thru a double throw switch
( 1+ 0_0 2+ ) and should be able to read either tank (both tanks have the fuel line conected with a brass T fitting and should draw fuel at the same rate anyhow.)
There is some corrosion in the Tach gauge and I wouldn't be suprized if the fuel gauge has some also.(the rest of the gauges read ok)
Is there away to check the gauge out without a sending unit at the tank? I did ground the fuel gauge sender wire with key on and got no reading/no pegging of the gauge.
-
When I turn the key on the fuel gauge "S" terminal sender wire has 12 volts thru it...If I connect it to a switch oposite the red wire to the fuel tank sender...With the switch on (12 volts thru the switch) it would be the same as conection straight to the fuel tank sending unit...Right? Correct !
I have read this 6 times now and it still confuses me some :rolleyes:
If I ground the fuel tank sender (good ground straight to the battery) and run the red wire from the gauge sender pole, Which has 12 volts when the key is on,to the + side of the fuel tank sender...I should get a reading??
with everything cnnected if you ground the red wire on the sender the guage should read full.
The tank having a resistor at the tank sending unit? 12 volts should be ok if it drops/resists the voltage at the sender?? I have no voltage to the sender at the tank as of now (the + red wire from the tank sender goes to a switch and that is it.)
I am mainly looking to use one sender from one tank and get a reading....then I will go thru a double throw switch
( 1+ 0_0 2+ ) and should be able to read either tank (both tanks have the fuel line conected with a brass T fitting and should draw fuel at the same rate anyhow.)
There is some corrosion in the Tach gauge and I wouldn't be suprized if the fuel gauge has some also.(the rest of the gauges read ok)
Is there away to check the gauge out without a sending unit at the tank? I did ground the fuel gauge sender wire with key on and got no reading/no pegging of the gauge.the guage may be bad .
If you need a guage I have a couple of spare guages laying arround here pay shipping and you can have one of em
C.T. :wink:
-
If you need a guage I have a couple of spare guages laying arround here pay shipping and you can have one of em
C.T. :wink:
Thanks, I will keep that in mind.
And Thanks for the offer, I have another set coming from Ebay :rolleyes: I bought the gauges last week mainly for the tach but the guy said all the rest of the gauges work (will see when they show up)
All the gauges in this boat got rained on while the previous owner had it sitting 2years. :rolleyes:
I grounded the fuel sender ground wire straight to the battery....checked the Ohms from the sender - ground to + positive and came up with(218.0 Ohms) I then hooked up the red gauge sender wire to the red fuel sender + wire and the Ohm reading went to (102.0 Ohms) I then turned the key on (open my eyes....LOL) the digital meter read (OL) open line.
I checked the voltage at the red wire on the fuel sender with key on and it read around 5.85 volts.(That would tell me that it has some voltage drop thru the sender....Hence a resistor.)
ALL other gauges are easyto wire....something about putting 12 volts to a fuel tank always gets me a little/lot nervous.
I guess for now I will wait and check out the other fuel gauge I have coming.
Could be as simple not having enough fuel to get a true reading (20+ year old gauge might be a little off anyhow.) BUT even grounded it doesn't respond.
I will put another 15+ gallons in it before the shake down run next week (7 gallons are in it now between both tanks?
