PDA

View Full Version : Fuel Guage problems


H20skeefreek
01-21-2005, 07:43 AM
The fuel gauge isn't quite right, lets see if we can figure this out.

with the old gauge, it would read empty when there was a little less than half a tank left. the new guage is reading FULL with the same amount of gas. The packaging says use a 90 ohms full sender (GM spec), but the instructions say I can get autometer part number 3262 sender, which is a 240 ohms full 33 ohms empty, which is standard marine stuff, and what should be on the boat. If I already have a 240-33 ohm sender do I need to buy thiers? why would this read FULL, and i mean FULL, all of the time? and more importantly, how do i fix it, do I need to get the autometer part?

H20skeefreek
01-21-2005, 11:27 PM
to the top

BriEOD
01-22-2005, 09:06 AM
Just an observation, but you are having some issues with this boat.

H20skeefreek
01-22-2005, 11:19 AM
actually, just a few. They mostly stem from my constant desire to improve upon everything. the alt. issue and the fuel guage issue are b/c I'm putting different gauges on the boat. I switched from and ammeter that never worked to a voltmeter, which i think is more valuable anyway. I have had a few issues with this boat, but I knew about them when I bought it, and it was factored in to buying it. sure, maybe I could learn a lesson about not fixing it if it aint broken, but what fun would that be?

When I bought the boat, i knew it needed a new alternator, new steering and it surged at WOT. I bought a new alt, changed (upgraded) to rack and pinion steering, and have now discovered that my surging problems are not carb related at all, but there are gelcoat shavings in my tank from the manufacturing process. They are clogging my anti-siphon valve, and starving the engine fuel at WOT, so the carb issues, weren't carb issues. I did a little rewiring of the nav lights, and sealed up the rubrail, and re-riveted. Basically by the time I get done with this boat, it'll be brand new, I just have some hurdels to get over.

When I buy something like a car or boat, I usually buy it as a project to fix up. Sure, I could have payed more and gotten a perfect boat. I could have financed a brand new Malibu, but I didn't. I payed what I could afford, now I'm trying to make it look like i couldn't afford it :laugh:

4 years ago, i bought a wrecked 1994 v6 mustang. it had low miles, but looked like crap. When I totalled it last year, it performed like a GT and it looked like a showroom condition Cobra. (Well before the moron in front of me stopped on the interstate and it was creamed) That's just the way I do things.

I fully expect that after a full year of ownership, and the time I put into it, it will run like it was brand new. I ski at a secluded site and rarely see another boat, but have no question abou the reliability when I go out, if the boat is not in tip-top shape, i don't take her out. And worst case scenario, I can swim.

jt76ss
01-22-2005, 04:56 PM
sounds like my boat!! haha

Laurel_Lake_Skier
01-22-2005, 06:59 PM
I had my sender in pieces a couple of times this past summer to free up the float. As I remember, when I checked resistance levels, there was little to none when the float was moved to the top (Full) and quite a bit when it was at the bottom of its travel (Empty). If you have any access to a variable voltage supply, you could connect that to your gauge and see what it takes to give a full and empty reading. From that, you could calculate the resistance needed since the fuel gauge acts like a volt meter.

BarefootWt
01-30-2005, 01:45 PM
You may want to do a visual inspection of the wiring behind the gage to insure there are no shorts. I had a situation where the insulation was missing on a small section of the fuel gage wire, and it was shorting against metal. This was a worse situation that yours, as my boat would not even start. Point being - a visual inspection of the wiring sometimes can surface an issue. Good luck.

JimN
01-30-2005, 01:55 PM
Laurel_Lake_Skier- you don't want to send voltage to the gauge, you want to vary the resistance at the sender. The pink wire sends voltage out, post gauge. The gauge's ground reference is supplied by the sender.

h20- verify the wiring to the gauge and the sender. Make sure the bracket holding the gauge in isn't in contact with the post attached to the pink wire. The bracket often is connected to ground and this would give you a full reading at all times.

H20skeefreek
01-31-2005, 12:08 AM
Laurel_Lake_Skier- you don't want to send voltage to the gauge, you want to vary the resistance at the sender. The pink wire sends voltage out, post gauge. The gauge's ground reference is supplied by the sender.

h20- verify the wiring to the gauge and the sender. Make sure the bracket holding the gauge in isn't in contact with the post attached to the pink wire. The bracket often is connected to ground and this would give you a full reading at all times.
Jim, I'll check that out, but the wierd thing is, if I shake the boat, the gauge shows FULLER than FULL, so I don't think that is the problem. I think the autometer sender must convert the 33-240 ohm signal to a 0-90 ohm signal. I'm not sure, but that's all I can figure. if the guage says it's for 0-90 ohm, how could it possibly work with a marine sender? I don't figure it can unless thier sender is a converter (is there such a thing?)

I'm painting my house right now, and we just had an ice storm yesterday, so the boat is on the back burner right now.

H20skeefreek
02-14-2005, 02:56 PM
Jim,

I'm just getting around to popping the dash back apart.

With the multimeter, with the key on (dash is alive) i'm showing NO resistance at the back of the fuel guage, and the guage reads pegged (full) With the key off (dash dead) i'm showing like 45ohms. This makes no since to me. How can I make this sucker work?

And I did do what you suggested, and wiring is AOK.

JimN
02-14-2005, 03:53 PM
Leave the key off. Ohmmeters don't work when there is voltage present unless you set the meter to measure a diode. Ohmmeters actually send a voltage out and then measure the voltage drop. Go to the sender and remove one wire. Attach the meter leads and check the resistance. If it's zero, you have a bad sender. It happens. Leave the wire off, go to the gauge and check the resistance from the pink wire to ground(preferably the ground going to the sender). You may still see zero and this would indicate that the wires may be chafed and shorting at the throttle, someplace at the rear or where there is a sharp edge for the wires to contact. This will need a visual inspection.

H20skeefreek
02-14-2005, 04:15 PM
Leave the key off. Ohmmeters don't work when there is voltage present unless you set the meter to measure a diode. Ohmmeters actually send a voltage out and then measure the voltage drop. Go to the sender and remove one wire. Attach the meter leads and check the resistance. If it's zero, you have a bad sender. It happens. Leave the wire off, go to the gauge and check the resistance from the pink wire to ground(preferably the ground going to the sender). You may still see zero and this would indicate that the wires may be chafed and shorting at the throttle, someplace at the rear or where there is a sharp edge for the wires to contact. This will need a visual inspection.

I've done all of that. visually inspected everthing, checked every scenario. The old guage worked, all I've done is changed the gauges. :rant: I need to figure out how I can make this guage work with my system.

I'll double check the sender, but don't know how it could go bad just by changing the gauge.

JimN
02-14-2005, 04:20 PM
Remember, these senders go bad whenever they feel like it.

H20skeefreek
02-15-2005, 07:31 AM
Leave the key off. Ohmmeters don't work when there is voltage present unless you set the meter to measure a diode. Ohmmeters actually send a voltage out and then measure the voltage drop. Go to the sender and remove one wire. Attach the meter leads and check the resistance. If it's zero, you have a bad sender. It happens. Leave the wire off, go to the gauge and check the resistance from the pink wire to ground(preferably the ground going to the sender). You may still see zero and this would indicate that the wires may be chafed and shorting at the throttle, someplace at the rear or where there is a sharp edge for the wires to contact. This will need a visual inspection.

ok, so when i disconnect one wire and test the resistance at the sender, I get completely random results, constantly changing. ranging from 45 ohms to 170+ ohms. obviously something is wrong with the sender, so I'll change that out ASAP.

at the back of the gauge, I always get 45 or 55 ohms (don't remember which, but it's constant.

there is no wire chafing, that I can see anyway I have visually inspect 98% of the wire.

JimN
02-15-2005, 08:31 AM
Before you buy a new sender, just remove it and test it. If the boat is moving at all, the sender will respond. With the sender disconnected, is the gauge still reading anything or empty?

H20skeefreek
02-16-2005, 08:16 AM
hmmmm.....interesting.....it still reads full. Is the guage bad?

Ski-A-Rees
02-16-2005, 08:20 AM
I have a problem with mine too! I can tell mine is getting power because the needle moves when I crank the boat but then it always reads empty! I'm not sure where to start looking!

H20skeefreek
02-16-2005, 08:25 AM
you should start by putting gas in the tank.......lol (=

maybe the other guy looking for advise shouldn't be giving it, but empty is no resistance. your sender is probably just bad, do the same things i've been doing. Pull the sender and measure it's resistance (key off and one of it's wires off I learned) move the arm and see if it changes. if it's always open (no resistance) then you just need a new sender. test the new one before dropping it in the tank so you don't have to take it out of the tank covered in gas if it doesn't work.

JimN
02-16-2005, 11:07 AM
H20- Are all three wires still hooked up to the gauge? I would verify their placement again, it sounds like the hot and input(pink) are reversed.

H20skeefreek
02-16-2005, 08:15 PM
Jim, they are all three still hooked up to the gauge, that was my thought as well, but the tabs are clearly marked Ignition Ground and Sender. and there is a warning on them about touching the ignition to sender and damaging the gauge, so I'm hesitant to switch them.

JimN
02-16-2005, 08:48 PM
Do you have access to another of the same gauge? It's acting like the one you have is wired wrong internally, if the external wiring is correct. Why not remove the gauge and wire the sender to the gauge, connected to just a battery, outside of the boat? If you have a 1L Pepsi bottle(or one like it), put some gas in it and you should be able to vary the reading if everything is good.

H20skeefreek
02-16-2005, 11:04 PM
I do not have access to another of the same gauge. But worst case scenario, I have the old one that won't match all my new gauges.

I'll give your suggestion a try, but don't I just have to move the arm on the sender? do I really need to put it in a jug of gas? The sender is just a rheostat correct?

JimN
02-16-2005, 11:22 PM
Sorry, I thought you had the other style. Yes, you can do that. Whatever type it is, simulate the range from empty to full. You already measured the resistance through its range, right? If the gauge shows full with the sender at empty and empty when disconnected, the sender isn't right for the gauge.

H20skeefreek
02-17-2005, 07:52 AM
after the test you had me do yesterday, I now see that the gauge is full, even with the sender disconnected (one side anyway). even though it says not to, i'm going to have to just reversed the ignition and sender wires, it has to be wired wrong internally.


and I just tested this morning. I went out, disconnected everything from the back of the gauge, including the light for it. I thought maybe that was messing something up. I switched the IGN and SEND, and it read even higher. When I switched the wires back, it went back down to the FULL it was at before. I just don't get it.

With nothing connected, there should be no resistance, which would be empty. It reads FULL with the sender connected or disconnected.

JimN
02-17-2005, 12:24 PM
If you removed the sender wire from the gauge and left the 12V+ and gnd connected and the gauge still reads full at this point, it's a bad gauge. If all 3 are still connected at the gauge and it reads full with the sender totally disconnected, the sender lead has to be grounding somewhere.

With nothing connected, it will approach infinite resistance. Zero resistance is a perfect connection. Did you check the resistance of the sender's ground wire yet? Also, post the resistance of the sender when the float is hanging down and when it's raised. When you connected the sender directly to the gauge, did the needle deflect at all?

H20skeefreek
02-17-2005, 10:20 PM
I'll check it out tomorrow afternoon. thanks for your help and patience so far Jim. I wish I could say i'm being as patient, I'm about to chuck the gauge in the woods.

TonyB
01-25-2006, 01:14 PM
H20,

Did you ever resolve your fuel gauge issue?

I have a fuel gauge that's works intermittently so I dropped in on this thread. Good stuff. except that this thread was like a special edition of "Matlock" where just when it's getting really good, the hour is up.

"Stay tuned for scenes from next week's exciting conclusion of Matlock."

"What the heck happened to next weeks conclusion?"

Don't leave me hanging.

H20skeefreek
01-25-2006, 07:04 PM
yeah, got it fixed. used the Skrew-it method. I replaced the gauge with a hash mark guage. Everytime I go to the boat I make a hash mark.

I know if I go skiing 4 times without filling up, on the 5th time, I'm gonna run outta gas, usually while i'm at 3ball.

TonyB
02-03-2006, 05:40 PM
yeah, got it fixed. used the Skrew-it method.

You owe me some bucks then, as I've copyrighted, trademarked, and patented the "Skrew-it" method.