The Stovebolt Site Forums The Shop Area The Electrical Bay Another gas gauge issue

OK, so I have looked through the forums. maybe someone can direct me as to what I am doing wrong.
issue: Gas gauge doesn't read anything other than empty

New 12V gas gauge (doesn't mean it is good) recheck to ensure one post went to key hot and the other went to the sender. Ground was cleaned and polished metal behind the gauge so that the metal gauge ground has a good contact (gauge to cluster) without any paint in the way.

Sender: I took the sender out of the tank and tried it full and empty. OHMS went from 30-0 or close enough for my liking. I moved and improved the ground to the body.

Gauge cluster is not in the dash, so I ran a wire with alligator clips from a known ground to a cleaned off ear on the cluster.

Truck is a 51 3100 that was upgraded (or downgraded depending on the viewer) to a 12V system. all new wiring was installed when rebuilding (rebel wire kit).

I assumed it was the ground so I even went as far as put a lead on the back of the "rectangular" ground on the back of the gauge. NOTHING!

So, before I hurt any animals, humans or myself, I figured I would take a Admin timeout, regroup, ask the team of experts here and then go back once I get my mind back on track.

Question: Any chance that I have the leads backwards on the backside of the fuel gauge?

Thoughts?

Chris

I purchased e of those new gauges

I found the needle set so high it would hit the bezel

...pic...

I had to push the bezel out so the needle would not get pinched


...click...

Sender on F post.
Power on E post

Yes you could have them backwards. As you know, your sender is good. So you've done well so far.

I am changing my advice because I'm approaching it more directly, sequentially and quickly so.......... if a person gets stumped:
Go to the bench:

1. The test ground wire, from the removed gauge, on the bench, must go directly from gauge ground pad to the battery neg post. Always remember when getting a base line/boiler plate reading, there must be NO MIDDLE MEN. (like a cluster ear) (like a "known" ground) Direct test wire only.
2. Test wire from battery neg post to sender flange. Direct test wire only. Battery or power source.
3. Test wire from battery positive post to gauge positive terminal. Direct test wire only. Battery or power source. Fuse can't hurt.
4. Short test wire from gauge sender terminal to sender center tap.
5. As we said in the past, all parts on the bench for testing. Power source can be battery charger or a battery. No truck wiring or truck grounds involved. Just test jumpers on the bench.
Cut out/isolate all possible wiring and ground failures until you get the stuff working together ON THE BENCH. Maybe you did that, can't tell from your description.

Commentary: This is not aimed at you NKkid. This is your first post on this issue. There have been so many, it's time to stop and establish order. Hope it's just your needle. DADS50 is an expert on this whole issue. Good man.

Commentary:
Come on people, this is common sense. In these seemingly difficult fuel reading cases when nothing seems right, can't find the fault, you can not keep asking why why why if you have not tested the sender for ohms, then test the sender and gauge together, doing it outside the truck on a bench. Do all the tests seen it videos posted and explanations posted. There certainly is enough of that info in past posts. YOU MUST eliminate the gauge and the sender from the equation FIRST. Eliminate, as in: Sure they are working. During bench testing we must have them 100% isolated from the truck and isolated from each other and then connected to each other during testing. Then we can move on to truck wiring, ground or power being the obvious issue. We CAN NOT move on until then. We CAN NOT keep guessing if it is the truck wiring, truck grounds, proper power to gauge, bad gauge, bad sender, wrong gauge, wrong sender, backwards hook up, wrong test procedure, wrong voltage, pinched needle, user error.............
After the two components are deemed good, ohm and voltage matched, we then carefully install a little at a time while testing all the way. Any other way is burning daylight. Do the work, we can not pin point it for you.

Thanks Bart/Dad

It is not a needle issue since the gauge is not working outside of the housing either.

I will go back and retest everything and then all together with direct wiring (no truck wiring). I appreciate the assistance with this since I am not the smartest when it comes to electrical. I have been shocked a few times and don't enjoy it! I will report back my findings. It is amazing how when you go back and start troubleshooting, you can find other issues. I know that my grounds were not up to standard, so I fixed them and added one for the fuel tank.

Question: what happens if I switch the leads? Will I hurt anything? I switched them, but removed quickly as the needle went off the gauge.

I would rather ask questions then make a costly mistake; which I have done a few times!

Thank you for your assistance!

Chris

Quickly is good. DADS50 gave you the hookup when he said "Sender F, power E". That means the terminal on the gauge that is on the "F" (full side) is the sender terminal and the terminal on the "E" (empty side) is power terminal.

Whew! That is what I have. At least I have one thing correct!

Chris

Leaning towards bad gauge unless you hook sender backwards or insufficient/wrong power, ground or ohmage. To the bench with you. Just because you wired to "key hot" does not mean you are getting hot to gauge terminal.


Troubleshooting

Rule 1. NOTHING is assumed.
Rule 1a: NOTHING.
Rule 1b: Read rule 1 and 1a.

Your testing this out of the truck?

Both the sender and cluster are out of the truck

Where are you grabbing your power from?

Where are you grounding for the test?

Can you post a pic of your test set up?

Right now it sounds like a bad gauge


Im only a pro at having problems with these gauges....for the last 8 years ive been using a reliable autometer gauge

Dad,

I tested both out of the truck. I tested the key hot and I have 12V on the "E" side of the gauge, I was using the trucks battery and upgraded wiring (tested). I am grounding to a bolt on the body that i know has worked for other grounds (heater and wipers). I don't have a picture yet. Let me see what I can do.

Here is what I have rechecked. All wires have the proper amount of voltage, sender has the proper OHMs.

I am going to pull the gauge out and connect it directly to the battery to see if anything happens.12V post to positive and I will run the ground (square on back of gauge) to the negative.

Time to go back to troubleshooting!

Chris

Sounds like you had a good test set up

You grounded the sender and the gauge to a good ground

With everything hooked up

Powered up

Raised and lowered the float. No movement

I don’t believe these repo gauges are manufactured in the same part of China as the iPhone

Where is the sender going to be on this next test?

Bart,

I know that I have a half tank of fuel. If the gauge moves at all, I will then move sender manually. Sorry failed to say I would leave it hooked up.

Brainstorming idea: I have a 0-60 ohm gauge at the house. If I hook this up in a 0-30 ohm system, it should read half of what I actually have in the tank. If this gauge works while hooked up to the current wiring, that would point At the first gauge being bad. Thoughts?

Chris

It may read different than you think, but if it reads, that's a good test of that gauge. But it does not prove as much as a bench test of the original two units.
P.S. I guess "leave it hooked up" means sender is in tank or laying on the seat or on a bench? Moving by hand gives me a clue but saying you have a half tank gives the reverse clue. It amazes me how words can be interpreted many ways. I wrote specs, I know. So no one gets away until they say specifically what they mean. In my profession it could cause a plane crash. I could assume you mean that it's in tank, but you know the rules. (1, 1a, 1b) That's why I asked it in a specific way. "Where is the sender going to be on this next test?". I kind of knew it would be hooked up. In this profession it takes 50 posts to fix a frickin gas gauge.

With all due respect, I would not want you on my Flight Instruments/Cockpit Displays team.

Not to be a pain but here is why words get screwed up. DADS asked if it was on bench and what power source. You said both out of truck. Then said you used the battery and a bolt on the truck and who knows what new truck wiring you are talking about. Then I thought they MAY BE on the bench but what does the "bolt" mean?. Then after that you said you were going to pull the gauge. So then I thought you did not get the message yet. All comes out and all goes on the bench. I said that was first. I said that was a must. I wrote a commentary about the need to start at the bench on a difficult issue. It did not have any alternative or use of a 90 ohm test gauge. We have only the words you post to study and think with. We give a direction and ideas for helping from far away.

It gives great heartburn to see that the inexperienced folks don't read and try to follow. If they don't know anything about the issue and need help.

The experienced folks use the suggestions, if they agree, and filter out what they don't need.

Which one are you?

I am the inexperienced that is trying to learning something I know nothing about which is dangerous. Gauge is currently not in the cluster. I will test it by pulliing the sender back out of the tank (temporarily back in to decrease the gas fumes) and test that way using the trucks battery, but external wiring. Sender will be placed in a garbage bag on my front seat so I don't drip fuel on the seat.

You are correct that if I place a new gauge into the system and it works, that doesn't mean anything about the old gauge. I was thinking that could confirm that my wiring and my sender were actually working by using a second means (confirmation)

Sorry for the confusion, I keep taking the sender in and out as I test it. Time to go purchase more wire!

Chris

PS: please don't ever let me near any flight instruments or cockpit displays..... If you do that, I will stick to keep you guys alive with my medical skills whenever required.

Chris, sounds good. I forgot the battery was in the floor on passenger side. So I guess you are working on the running board or a milk crate as your bench? So as not to have to remove battery?
The bench procedure is exactly for not having to take gauge and sender in and out. They are both very difficult to reach and deal with. So making sure they work out of the truck is the first step. You are now finally at the first step. Are you using forceps instead of alligator clips?

If you have a motorcycle, ATV, boat or riding lawn mower, you can use their 12V battery. You can use jumper cables from your truck to a table if it is easier. I always use my 12V battery charger, sometimes with a fuse, to do electrical testing on the bench.

I hope that DADS50 will post his bench test video.

I will report my findings! It will probably not be tonight since I want to watch the Washington Capitals beat up the the Lightning. Maybe tomorrow I will start step one!

I have watched DADS video, but would love to watch it again to ensure I do it right. I am not sure where I saw it posted.

In case I didn't mention it, as hard headed as I am, I really appreciate your assistance as I attempt to learn something new.

Chris

Very glad to help any way I can. Your determination is to be proud of.
Trying to write posts that can be searched and used to eliminate repeats. Ain't workin. I know how it is. I search and search and read and read and I get bored they don't talk about my specific issue. So I ask a question and someone says they have answered it 20 times. In fact, I learn so much in trying to answer because I have to look up things I used to know and read new things on here all the time. I am really A.I. I do use my ElectroMechanical Engineering/Designing past life to help me and 50-60 years of working on my own old vehicles......and HotRodJerry.

I really enjoy when someone gets it fixed without taking to a shop. This is a virtual shop. Hopefully.

Your Nationals just swept My Diamondbacks.

update:

I pulled the gauge and the sender out. I wired directly to the battery (positive and negative). Sometimes when I moved the sender, I got the gauge to move. I then put another gauge in place of the in1 itial gauge and had the exact same results. SO.....I went back to rechecking from the beginning. The sender was pushing out 21 OHMS sometimes, but not all the time. Most of the time it was not sending out anything. The highest I could get either gauge to move was from "E" to "1/2 tank".

Result of testing: it was not the gauge, it was the sender despite originally getting the correct 0-30 OHMS. Time to purchase a new sender and have it here ASAP so that I can drive my truck with confidence that I am not going to run out of gas.

Next test: ensuring that the new sender works with the gauges and then retest again once it is actually in the truck on the "every day" wiring.

Thanks guys!

Chris

I keep ohm resistors of diffrent sizes from radio shack in my electrical took kit

A way to test a gauge without a sender

...click...

I may have to look for some.

Glad you did the correct test and glad you are going to be SURE of the new one. Real sure, before installing in truck. You have saved a lot of time and headache. The sender was intermittent it seems, but don't conclude that yet. This gas gauge/sender can be a tricky business. Good job. Don't throw the old sender away yet. Let us know the final outcome.

Will do Bart! I am also going to try the resistor idea since I am trying to learn a little bit of this electrical thing. My luck, I have 2 issues going on!

Looks like DADS50 is using 10 20 30 to check gauge. I don't think you need to do that unless you want to play.

You still have not proved you have a good gauge either

Very true DADS. I figured that if both gauges are doing the exact same thing, then it "probably" isn't the gauge. I will use the resistors and see if I can get the gauges to move correctly. I am currently waiting on the resistors to arrive in the mail.

Chris

Ok, step in the right direction! Everything works when I bench test after I replaced the sender.
I next tried testing with installed wires (key the music)....when gauge is in cluster and gauge frame is grounded I get a little movement. When gauge is NOT in cluster but grounded through a clipped on wire, it works!

Here is what I have tried. Sanded cluster connection points to bare metal. Tried clipping onto housing (trying to check gauge ground)- nothing. How does everyone get gauges to ground? Is there a trick to this?

Chris

RED: Obviously it's not grounded in the sense that there is not a good GROUND PATH all the way to the battery. SO just think it thru and study the path from gauge back pad and be sure all touch points are clean metal, all screws joints are tight and all ground wire connections are clean and tight. Chris you have either not sanded the correct spots or the spots you sanded are not touching good enough or are touching unsanded. I don't know how the cluster is built or attached to dash, but you do. Be sure the dash itself is grounded to that body. ALSO your comment ...."and gauge frame is grounded"...what exactly do you mean? how is it grounded? by a test wire or normal mounting? This is taking too long. Touch/fasten a ground test wire to gauge frame, mount gauge in cluster, touch other end of wire to various places to see where ground is or isn't, start right next to gauge and move outward. Why can't you take out the whole cluster and get gauge working as mounted, then you know that all cluster metal is grounded to gauge? Then sand where cluster mounts to dash?

GREEN: What housing? If you are "clipping" onto gauge housing when outside of cluster and same clip place when inside (mounted to) cluster, it has to still work. Provided that the other end of the test ground wire has not been moved from wherever you have it attached. You can not change methods or connection spots during a test.

Housing was the ear that bolts to the dash. I agree that it’s a grounding issue. I will keep sanding.

Just a thought: what happens if I were to drop sodder onto clean (no paint) spots in an attempt to ensure that it’s touching. Just a thought in case gauge is not touching cluster body

I will keep working on the ground.

Just read what I wrote, I was still typing and editing. Do your testing over. You need to understand about testing. It is the key to troubleshooting. Without tests you have NO WAY to find problems. Can you or can you not take out cluster? If you did take it out, did you or did you not get gauge to work from grounding a cluster mounting ear. If not, take it out and get gauge to work from grounding at each ear, one at a time. (on the "bench"). See what you discover, that is what testing is for. Slowly realize where ground is lost. If all ears ground and gauge works, proceed to mount cluster. I assume you are using the sender each time you are testing gauge. I assume you keep checking voltage in case you loose voltage somehow during testing. You must not let two things happen at once or you will be in the nut house like I was until escape. This is taking too long because you are jumping to fast and wanting to do things like solder blobbing. Go back and test. You have the answer right there at your finger tips and rushing past it. I am with you Chris. You are going to get this. Watch your words, don't just say housing, be specific. One time housing was gauge, other time it was a cluster ear. CAN'T do that on a over the internet help forum. Tell where each end of test wire is connected on EACH test cycle. I guess your problem is you don't have a "bench" or a power supply so you are doing the best you can. It's still doable on the running board. Please read all several times I'm out of energy.

Ok, let me rephrase. Gauge Cluster is not in the dash yet since I am working out the demons one at a time.
Step one: bench test was a success, gauge moved with sender (0-32 ohms) as it should.
Step two: once I knew gauge worked and sender worked, I hooked everything up to truck wiring and added ground to back of gauge (prior to installation into the gauge cluster) gauge/sender was working!
Step three: put gauge into cluster and rehooked/rechecked all connections. Cluster was cleaned of paint at all points gauge should touch. Gauge didn’t move like it did prior to getting put into cluster. It moved from E to 1/4 tank. With cluster not in dash. Ear was cleaned of paint for grounding purposes/future bolting.
Step four: returning to step 2 since it was the last working step. Trying to figure out the grounding and recheck my work. I am currently cleaning off more paint (larger diameter) and going to clean cluster area without paint better.

Can you describe your bench test? (When it worked)

How did you gound it if it was not in the cluster?


Do you have a pic?

I understand you tested the sender and the gauge "on the bench" and the sender made the gauge read as it should when float was articulated. I got that.

Now:
Let me know when the gauge works when mounted in the cluster and test ground on cluster ears. Cluster NOT in truck. Sender operating the gauge. This would still be a "bench test". Stop there and report. Still can't tell if you got there or not. As you can see DADS50 is not sure either. STOP installing anything into truck UNTIL this test is successful and you have reported.

Just to say it one more time, Test the gauge while mounted into cluster with cluster REMOVED from truck. Test gauge using sender, with ground wire clipped at each ear, one at a time and report when that test is successful on all ears and STOP. Make sure you follow this exact test. Then wait for the next phase.

All you have to do it follow instructions. We will get there faster. You are holding this back by not following one simple test and reporting. You go on and on about other tests you are doing and removing this and that. Please stop doing that.

We are making sure that the cluster itself is carrying ground from the gauge to it's mounting. When it does, over and over on every ear, we will advise next step.
It sounds like your step three is what I am saying and it did not pass but not sure of the exact setup of test, not sure each ear was tested, not sure if other end of ground test wire was to the battery.

DADS50: There is only one discussion on the entire WWW and it's on Stovebolt, regarding how gauge is actually grounded. You were posting on it. It seems like the consensus is that the center slug or solder bump is not supposed to touch anything and has a clearance hole between the stud holes. This allows for only the "ground plate" to touch the inside of can. Which is a good thing. This ground is never discussed by trouble shooters. All anyone ever says (like me) is gauge needs to be grounded. The can and the plate need cleaned to bare, but it does no good if they don't touch tightly or cluster can "oil cans" going down the road. Every other ground place regarding this ongoing fuel reading system ground issue, that many have, can be screwed and bolted and crimped and cleaned and sanded and will become perfect, except this.

In my opinion, in an effort to get good ground contact, the nuts are sometimes over torqued causing other troubles. Like twisting the gauge guts or shorting something out on gauge. In my opinion If the can is bent away, or warped, it will not allow gauge to ground and finding that anomaly can caused some serious headaches. A couple of well placed rivet heads on can might help.

I am just think about this without ever having an AD truck because I like to find and help fix. Chris, this could be your problem.

Dad,
bench test (sitting on truck seat) was positive wire running to “e” side of gauge to positive battery post. Sender wire from “f” side to sender input (threaded bolt on sender). Ground was connected to round sender housing where bolts hold it onto tank to negative battery post. I also ran a wire with clips from gauge ground (back of gauge, NOT cluster) to negative battery terminal. (Where I misunderstood/jumped the gun was I thought I was supposed to assemble, one wire at a time and retest after each connection. Thinking that would identify any problems when something failed to work)

I will go back to “bench test” and figure out gauge/ cluster ground issue like Bartamos stated above.

Update: gauge is not making good contact with inside of cluster. I was able to slip a small shim to test connection this issue. With shim, I am getting full range of motion. Without, I only get Partial movement. (Cluster ear was used as ground.) Time to clean it up better, clean other “ears” off also.

If needed, Can I use a couple small drops of sodder inside cluster to close up any gaps? I know you stated small rivets previously.

Baby steps!

Thats odd

Should be a clear path

...pic...

There are two little positioning ears on the cluster is your gauge hanging up on one of the ears?

No, I started with that issue! After slapping myself for being stupid, I fixed it and laughed. Now, best way to fix it? Bend back of cluster towards gauge, sodder, rivet, etc. thoughts?

If they are not hanging up on those positioning tabs and you can get the plate to touch better, that's OK. There are a lot of things you could do but some may cause the studs to touch metal. Be careful. Solder won't stick to the can. Not sure what raising gauge up with shim or solder or rivet head or dimple would do to the overall assembly of gauge. Face may hit something.

Not sure what going on with your gauge and gauge housing

Does the back of your guaue look like this
...pic...

What is preventing it from resting flat without modification?

Are the notches in the correct spot in the fiber board?

Has your housing been bent out of shape?

After checking what DADS50 says and trying to get contact without modification, if cluster can won't contact gauge ground plate and you prove that is the whole problem with this isue,

then:
If your ground plate looks like the pic DADS50 just posted, you can solder a wire to the solder blob and run the wire to ground. I have seen some gauges that have a round slug between the studs that is not supposed to touch anything. If yours is not like that and the center hole is just to clear the solder blob, then you can solder a wire. Be careful not to get things too hot and lose the existing solder connection. You probably should use a non flame solder gun and probably don't need to add solder. Don't let the solder flow to a bigger blob or it won't clear the hole.

After soldering wire and assembling gauge into cluster can, you may want to epoxy the wire to outside of cluster can as a strain relief.

The proper way to solder a wire to something is to "tin" it first. This just means twist the stripped strands, get wire hot and apply a thin coat of solder to wire. Solder should soak thru all strands.Then solder wire to the ground plate solder blob. Heat the wire until it sinks into the blob. That ground plate is a "heat sink", so may be difficult. Do the soldering with gauge outside of cluster.

Yes, gauge looks like dads picture. I guess I will be doing it on Monday Afternoon! Thanks guys! I will report back once step is completed and tested.

Chris

Gitter done.