Bad gas gauge

Steveo · 06-11-2012, 12:44 PM

Put the boat in the water and noticed my gas gauge wasn't working. Any suggestions on how I can isolate the problem. Old boat - 1988 Four Winns. Gauge itself gets power, nav light works on it. Gauge moves slightly when key turned on. Wiring to gauge and from sensor is fine. Any suggestions on how I isolate it to the gauge itself or the sensor.

Thanks

SAB1 · 06-11-2012, 02:57 PM

I a boat that old I would bet it is the sending unit especially if the fuel gauge has power and the terminal connections are clean.

whosnext8302 · 06-11-2012, 07:04 PM

just had the same problem, called the company that made the gauge and sender. I was told to take the wire off the sending unit and ground it to the tank, if the gauge goes up to full the sending unit is bad

hope this helps

Dave R · 06-13-2012, 08:41 AM

Consider replacing the gauge with an Lowrance LMF-200 multi-function gauge and an EP-60R fuel flow sender instead of repairing the old system. You program your tank size into it and it and it gives you extremely accurate fuel level data based on the flow to the engine, not the position of the sender. You also get fuel flow data which can be very handy for finding your optimum cruising speed. Add speed data with a GPS or a paddle wheel sensor, and you get real-time MPG in addition to fuel flow and and fuel level.

Baja Guy · 06-17-2012, 09:22 PM

If you don't want the whiz bang electronics you can go through the normal stuff too. Go to the hardware or auto parts store and get a tiny tube of dielectric grease, a brass or other metal brush, and a little bit of fine emery cloth.
Disconnect the battery at the negative post. Then, 1 at a time remove, clean up & reconnect the electrical connections to the gauge, the sender and the connector plug if there is one. Just brush or buff the contacts enough to remove any corrosion and create a slight metallic shine, if the shine is silvery on copper contacts that's OK. It means they have been tinned to enhance conductivity. Don't remove the tinning any more than necessary to get a clean connection. The emery might not be necessary unless the contacts are really green with corrosion.
Most 4 Winns I know of your vintage are OMC and I don't know their wiring, I have an 89 Mercruiser. On Merc's there is a master plug with 10 or 11 contacts, A couple of years ago I had to individually clean each plug "male" contact and then stick a razor down the splits in the centers to spread each post a bit to get them to make good contact with the receptacle end of the plug. On the receptacle end I rolled up my emery cloth to put it in the holes to clean them up. Now all my gauges and switches work properly, before I would get intermittent failures.
Once the gauge is working the grease is good for slowing future corrosion, just put a little bit on each contact. It's OK if it gets between the lead and the post, dielectric grease is conductive. So don't use so much that it makes a path to ground (metal) or to another connector.

Steveo · 08-28-2012, 01:39 PM

I wanted to thank everyone for their input to my problem. Through your help I was able to isolate the problem to the sending unit. Called Melvin Village Marina and they had a couple of options. One work particularly well. After a whole 30 bucks I was up and running (but not out of gas)

Kamper · 08-29-2012, 07:41 AM

Thanks Steve! We often don't hear which suggestion solves the problem. It's a lot like asking...

"How do you keep a member of the Winnipesaukee Forum in suspense?"

06-11-2012, 12:44 PM	#1
Steveo Senior Member Join Date: Apr 2004 Posts: 523 Thanks: 47 Thanked 123 Times in 63 Posts	Bad gas gauge Put the boat in the water and noticed my gas gauge wasn't working. Any suggestions on how I can isolate the problem. Old boat - 1988 Four Winns. Gauge itself gets power, nav light works on it. Gauge moves slightly when key turned on. Wiring to gauge and from sensor is fine. Any suggestions on how I isolate it to the gauge itself or the sensor. Thanks

06-17-2012, 09:22 PM	#5
Baja Guy Member Join Date: Dec 2009 Location: Nashua, NH Posts: 45 Thanks: 3 Thanked 3 Times in 3 Posts	If you don't want the whiz bang electronics you can go through the normal stuff too. Go to the hardware or auto parts store and get a tiny tube of dielectric grease, a brass or other metal brush, and a little bit of fine emery cloth. Disconnect the battery at the negative post. Then, 1 at a time remove, clean up & reconnect the electrical connections to the gauge, the sender and the connector plug if there is one. Just brush or buff the contacts enough to remove any corrosion and create a slight metallic shine, if the shine is silvery on copper contacts that's OK. It means they have been tinned to enhance conductivity. Don't remove the tinning any more than necessary to get a clean connection. The emery might not be necessary unless the contacts are really green with corrosion. Most 4 Winns I know of your vintage are OMC and I don't know their wiring, I have an 89 Mercruiser. On Merc's there is a master plug with 10 or 11 contacts, A couple of years ago I had to individually clean each plug "male" contact and then stick a razor down the splits in the centers to spread each post a bit to get them to make good contact with the receptacle end of the plug. On the receptacle end I rolled up my emery cloth to put it in the holes to clean them up. Now all my gauges and switches work properly, before I would get intermittent failures. Once the gauge is working the grease is good for slowing future corrosion, just put a little bit on each contact. It's OK if it gets between the lead and the post, dielectric grease is conductive. So don't use so much that it makes a path to ground (metal) or to another connector. __________________ 1989 Baja Sunsport 196, Mercruiser 5.7, For Sale 1987 Formula 223 LS with 1997 350 Mag

08-28-2012, 01:39 PM	#6
Steveo Senior Member Join Date: Apr 2004 Posts: 523 Thanks: 47 Thanked 123 Times in 63 Posts	Gas gauge fixed I wanted to thank everyone for their input to my problem. Through your help I was able to isolate the problem to the sending unit. Called Melvin Village Marina and they had a couple of options. One work particularly well. After a whole 30 bucks I was up and running (but not out of gas)

06-11-2012, 02:57 PM	#2
SAB1 Senior Member Join Date: Feb 2012 Location: Tuftonboro Posts: 1,165 Thanks: 182 Thanked 297 Times in 220 Posts	I a boat that old I would bet it is the sending unit especially if the fuel gauge has power and the terminal connections are clean.

06-11-2012, 07:04 PM	#3
whosnext8302 Junior Member Join Date: Aug 2008 Posts: 4 Thanks: 4 Thanked 1 Time in 1 Post	just had the same problem, called the company that made the gauge and sender. I was told to take the wire off the sending unit and ground it to the tank, if the gauge goes up to full the sending unit is bad hope this helps

The Following User Says Thank You to whosnext8302 For This Useful Post:
Steveo (06-12-2012)

06-13-2012, 08:41 AM	#4
Dave R Senior Member Join Date: Jul 2004 Posts: 2,974 Thanks: 246 Thanked 736 Times in 438 Posts	Consider replacing the gauge with an Lowrance LMF-200 multi-function gauge and an EP-60R fuel flow sender instead of repairing the old system. You program your tank size into it and it and it gives you extremely accurate fuel level data based on the flow to the engine, not the position of the sender. You also get fuel flow data which can be very handy for finding your optimum cruising speed. Add speed data with a GPS or a paddle wheel sensor, and you get real-time MPG in addition to fuel flow and and fuel level.

The Following User Says Thank You to Dave R For This Useful Post:
Steveo (06-13-2012)

08-29-2012, 07:41 AM	#7
Kamper Senior Member Join Date: Jul 2005 Location: Thornton's Ferry Posts: 1,296 Thanks: 67 Thanked 166 Times in 126 Posts	Thanks Steve! We often don't hear which suggestion solves the problem. It's a lot like asking... "How do you keep a member of the Winnipesaukee Forum in suspense?"