fuel gauge/sending unit
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Boat Maintenance
Forum Discription: Discuss maintenance of your Correct Craft
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=3561
Printed Date: January-15-2025 at 9:34am
Topic: fuel gauge/sending unit
Posted By: wormwarner
Subject: fuel gauge/sending unit
Date Posted: May-13-2006 at 10:52pm
| My fuel gauge reads full when I turn the key to run. It drops to empty when off. I put in a new sending unit and it is still doing this. I can remove the ground wire and it will drop to empty, I put it back on and it pegs full. Is my gauge bad? Did I get a bad sending unit? Or is the ground not right? I have a 1987 2001. One more question, should there be two wires coming off the ground post. I have one going to the filler neck of gas tank and one to anchor light. Thanks |
Replies:
Posted By: nuttyskier2002
Date Posted: May-13-2006 at 11:37pm
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When you installed the sending unit was it just like the one that came out of the tank? If it's not, the float might be getting obstructed and not falling as fuel is being used. Did you install it the same way the old one came out? If everything is okay with the sending unit it sounds like the gage is working and you might having a wiring issue. There's a previous thread posted here on troubleshooting the gage. ------------- 95 Malibu Echelon w/Mercruiser 350 Magnum Skier Former boats: 88 Ski Centurion Tru Trac II 59 Chris Craft Capri (woody) |
Posted By: wormwarner
Date Posted: May-14-2006 at 12:48pm
| Sending unit was like the old one. Went in the correct way. It does not slowly go to ful when key is turned on, it pegs the needle hard. I disconnect ground wire and it falls to empty. I will check out thread on gauge. Thanks |
Posted By: David F
Date Posted: May-15-2006 at 11:12am
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Could be that that one of the gauge wires is shorted to ground. On the back of the fuel gauge, you should have three wires: ground, "+", "S" for sending unit. Obviously, the guage is getting power because it pegs to full. Disconnect the wire at the "S" and run a length of wire directly from the "S" to the sending unit itself. Turn key on and see what happens. If the guage now works correctly, then you have a short to ground in the original wiring. If no difference, look for incorrect wiring at the sending unit or problems with the sending unit. ------------- |
Posted By: wormwarner
Date Posted: May-15-2006 at 5:43pm
| Thanks David for the advice I will try this and let you know how it goes. Should that wire "s" be pink? |
Posted By: marks
Date Posted: May-15-2006 at 6:24pm
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wormwarner,
I had problems with my sending unit last season, and I believe the "s" wire was pink. If your wiring to the gauge checks out okay, you can do an easy test on the sending unit. Remove all of the wires from the sending unit, then use an ohm meter to check the resistance between the ground post and center post on the sending unit. You should read something between 20 ohms (full) to 220 ohms (empty), depending on the amount of fuel in the tank. If you read 0, then there is a short in the sending unit. |
Posted By: wormwarner
Date Posted: May-15-2006 at 9:31pm
| I disconnected the "s" wire from gauge then ran a wire direct from gauge to sending unit. I got the same results, the needle went to full. I'm stumped. |
Posted By: wormwarner
Date Posted: May-15-2006 at 10:28pm
| Is there any way to run another ground wire from sending unit to ground or does it need to tie in with gauge |
Posted By: David F
Date Posted: May-16-2006 at 8:57am
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Do the sending unit test as Mark suggested. If you get the results mentioned, replace the sending unit. IMHO, 9 out 10 fuel gauge problems are the result of varnished or faulty sending units. ------------- |
Posted By: marks
Date Posted: May-16-2006 at 1:58pm
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wormwarner,
Here are a couple more suggestions: Run a new ground wire to the fuel gauge. The dash grounding harness used by CC in the older boats is subject to corrosion. Go to Radio Shack and buy a 47, 100, or 150 ohm resistor. The 100 ohm would be my first choice. Remove the "s" wire from the back of the fuel gauge and tie the resister directly between the fuel gauge ground and "s" post. If the gauge still pegs full, then you probably have a bad gauge. |
Posted By: wormwarner
Date Posted: May-16-2006 at 3:23pm
| Thanks guys I will give those things a try. I hope it is a bad sending unit, although it is brand new. I bought a new one trying to fix this current problem. |
Posted By: wormwarner
Date Posted: May-16-2006 at 4:10pm
| When I run a new ground wire to fuel gauge, is that coming direct from sending unit ground post back to gauge? Do I run ground from gauge to another grounding point, leaving ground wires the same at sending unit? Or do I do the previous but tie sending ground to new ground at gauge? Sorry for all the questions I enjoy working on my boat, but electrical whiz I am not. Thanks for your help David and Mark. |
Posted By: marks
Date Posted: May-16-2006 at 4:29pm
| Under your dash, you should see a grounding block. First try running a wire directly from the grounding block to the ground post on the gauge. If that doesn't work, then run another ground wire from the grounding block back to the sending unit. |
Posted By: wormwarner
Date Posted: May-16-2006 at 8:39pm
| Thanks guys its working. I disconnected the gauge wires, removed the gauge out of dash. I cleaned connections and sprayed contact cleaner on and in gauge put back in and its working. I'm sure I'll have many more questions. Thanks again. Already have one, where is the warning alarm located? Mine is not working. I am not sure it is on boat. |
Posted By: lenman
Date Posted: March-16-2024 at 6:50pm
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Hey guys, I am having to replace the gages on my 2006 super air 220 I have all new Faria gages but they are basic gages - Ignition, sending and ground. Replacement gages don't exist. Faria told me to send them $6,000 and they would send me a whole new system, not my first choice.LOL I went through the wiring system and found an unused wire labeled FUEL. I assumed this was the ignition wire, I also used a wire tracker and found this wire is connected to the red or pink wire coming from the sending unit. This circuit is powered by the ignition switch but with the power off it still is connected to the sending unit as verified by the wire tracker. I hooked up the ignition wire to the gage on the ignition post and grounded the sending side of the gage and got a reading. This doesn't make sense to me. not the first time I have wired a boat or car but don't want to screw this! Can anyone help?
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Posted By: KENO
Date Posted: March-17-2024 at 7:27am
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Here are a couple of pictures of a basic Faria fuel gauge The first one has the 3 connections marked with a marker since the factory marks are kinda small and hard to see. https://ibb.co/WvP9YcD" rel="nofollow">  The second one shows what's hooked to each connection Pink wire from the sending unit goes to "S", Black ground wire under dash to "G" and power from the key switch in the Run position to "I" (same power that's feeding the other gauges when the key is in Run) It should be a Purple wire The spade connector at the top is power to the light bulb https://ibb.co/sbWGVFM" rel="nofollow">  Not sure from your description if that's how you have things wired, but that's how it should be. The sender is a standard 33 to 240 ohm marine unit. If the tank is empty the sender should be about 240 ohms on the pink wire and if it's full it'll be about 33ohms The gauge can be checked for response by grounding the Pink sender wire back at the tank or at the dash and with the key in Run, the gauge will peg to the Full side. Unground the sender wire and it should be telling you tank level with the key in Run. If you remove the sender wire, the gauge will be pegged low. Also thought I'd mention that you get this weeks award for what may be the oldest thread resurrection on CCF.......6514 days between the previous post and your new post
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