'66 Newport fuel gauge not working

5fty7vn

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I stopped to put gas in my Newport the other day. When I left the gauge read a half tank (which is accurate since I can make fuel last a while considering it's my weekend only driver). About 15-20 minutes later I happened to look down at the dash and saw the gauge was on "E". I didn't lose any fuel anywhere so I know I have fuel in it. I'm wondering if a fuse blew and, if so, which one is it? Or did something else go out in the tank??? Any ideas?
 
Take a set of alligator clips and hook them to the sending unit and a good ground, does the gauge move? If not take a test light and hook it to a good ground and disconnect the lead to the sending unit, if you are getting power to the sending unit lead you should get a flashing test light when the test probe is connected to the sending unit lead. If there is no power, it could be a bad connection someplace, a bad fuse, or a bad cluster voltage regulator. You can test the fuse with the test light, both ends of the fuse should light the test light. If there is power to the sending unit lead, most likely the sending unit or the float has expired. Good luck.

Dave
 
Take a set of alligator clips and hook them to the sending unit and a good ground, does the gauge move? If not take a test light and hook it to a good ground and disconnect the lead to the sending unit, if you are getting power to the sending unit lead you should get a flashing test light when the test probe is connected to the sending unit lead. If there is no power, it could be a bad connection someplace, a bad fuse, or a bad cluster voltage regulator. You can test the fuse with the test light, both ends of the fuse should light the test light. If there is power to the sending unit lead, most likely the sending unit or the float has expired. Good luck.

Dave

Or the ground strap from the sending unit nipple to the metal fuel line rusted off, fell off or broke off. They are available or 2 small house clamps and a piece of wire with the ends stripped will work (since the rubber house between the sending unit and the metal fuel line can't make a ground). Sometimes you get lucky and it is this simple. Hope this is your problem.
 
Well........went to start the car up, did nothing at all..........this is what I saw..........

20190827_100818.jpg
 
Did we get an answer here? I have the same problem. New sending unit, good ground...I'm thinking it may be a stuck or broken gauge voltage regulator.
 
If your gauge is stuck in the middle and does not move with the key either on or off, it is a bad gauge. If the car has sat for a long time, you will frequently find spider webs blocking the movement.

Dave
 
If your gauge is stuck in the middle and does not move with the key either on or off, it is a bad gauge. If the car has sat for a long time, you will frequently find spider webs blocking the movement.

Dave
This car has been sitting...but today (only had car a couple weeks and driven it less than a hundred miles....maybe...odometer doesn't work either) I got a peek at the needle and it crept up from the empty side. Tank is probably 3/4 full. I hadn't been able to see the needle at all until today.
 
This car has been sitting...but today (only had car a couple weeks and driven it less than a hundred miles....maybe...odometer doesn't work either) I got a peek at the needle and it crept up from the empty side. Tank is probably 3/4 full. I hadn't been able to see the needle at all until today.

Usually, if the gauge moves, the CVR is still working. Try disconnecting the lead to the fuel sending unit and ground it to a good ground. Now briefly turn the key on, if the gauge climbs rapidly and starts to peg, the gauge and the VCR are good. (Don't leave the key on it can fry your gauge) Some of the replacement sending units were made in China and have defective floats or defective resistance wires. If the gauge does not move, most likely the cluster VCR is bad.

Dave
 
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Usually, if the gauge moves, the CVR is still working. Try disconnecting the lead to the fuel sending unit and ground it to a good ground. Now briefly turn the key on, if the gauge climbs rapidly and starts to peg, the gauge and the VCR are good. (Don't leave the key on it can fry your gauge) Some of the replacement sending units were made in China and have defective floats or defective resistance wires. In the gauge does not move, most likely the cluster VCR is bad.

Dave
I'll try it...I just put a new tank and sender in it. The sender I took out looked new also and the gauge didn't work. I was careful about the ground strap and cleanliness of everything...
 
Has anyone found a DECENT SOURCE OF SENDING UNITS? Mine, purchased 3 yrs ago, is crap, reading somewhere between 40-70 ohms, and consequently not much good can be made of it with a decent working gauge. I would like to get a somewhat better sending unit, if such can be had. I too am driving a 1966 Newport. Since my unit doesn't change value over most of the range of motion, I see little point in dropping $60+ for that nice interpolator made for GM sending units, but applicable to Mopars.
 
Ok....it gets weirder. With a full tank, my gauge will go up to about half just after the car is started and the amps are higher due to battery recharging....then it drops down to a quarter or so. I gotta get a working fuel gauge OR a working odometer...a man should have both, but needs at least one!
 
I gotta get a working fuel gauge OR a working odometer...a man should have both, but needs at least one!

You don't need any of that crap, so why are you worrying about it? Just rip out the dash and be done with it! After all, you said it yourself that simplicity is the greastest safety feature!!
Simplicity is the greatest safety feature.
 
Has anyone found a DECENT SOURCE OF SENDING UNITS? Mine, purchased 3 yrs ago, is crap, reading somewhere between 40-70 ohms, and consequently not much good can be made of it with a decent working gauge. I would like to get a somewhat better sending unit, if such can be had. I too am driving a 1966 Newport. Since my unit doesn't change value over most of the range of motion, I see little point in dropping $60+ for that nice interpolator made for GM sending units, but applicable to Mopars.
Have the original rebuilt. Never used these guys, but have heard good things. They are about 45 minutes west of me. Rebuilt Fuel Sending Unit Specialist

Otherwise, it's my opinion that ALL the aftermarket sending units are sourced from the same manufacturer. If you start looking around, they all have the same part number possibly with a different prefix/suffix depending on the vendor.
 
Have the original rebuilt. Never used these guys, but have heard good things. They are about 45 minutes west of me. Rebuilt Fuel Sending Unit Specialist

Otherwise, it's my opinion that ALL the aftermarket sending units are sourced from the same manufacturer. If you start looking around, they all have the same part number possibly with a different prefix/suffix depending on the vendor.

I was afraid that was the case. The Chinese have a LONG history of playing at changing facades to fool people. Such has ever been their way. Think I WILL check out these rebuilders, and thank the Lord I had the sense to save the old unit.
 
I was afraid that was the case. The Chinese have a LONG history of playing at changing facades to fool people. Such has ever been their way. Think I WILL check out these rebuilders, and thank the Lord I had the sense to save the old unit.
Don't blame the Chinese. They aren't selling, they are manufacturing.

I think the main manufacturer is Spectra and they are a Canadian based company and they are manufacturing (most likely) in China, just like everyone else. It may even be a Spectra owned facility, but that's a guess on my part.

If you look at the vast majority of repo parts, you'll find that, while there's a bunch of sellers, there's only a couple manufacturers.
 
Don't blame the Chinese. They aren't selling, they are manufacturing.

I think the main manufacturer is Spectra and they are a Canadian based company and they are manufacturing (most likely) in China, just like everyone else. It may even be a Spectra owned facility, but that's a guess on my part.

If you look at the vast majority of repo parts, you'll find that, while there's a bunch of sellers, there's only a couple manufacturers.

I WONDER about Spectra. Actually not sure if they're even fronting the 1966 Newport's unit. I certainly didn't find one in the 2 years I searched before settling on what I now have! Spectra makes EVERYTHING BUT a fuel sending unit for a 1966 Chrysler Newport.

I've seen a number of vendors for a unit like what I bought. I suspect the prior unit I had in my gas tank MAY have been a Spectra, of a sort not meant for '66 Newports. (I see in the 1966 catalog that the fuel sending unit, 14-72-1 looks like what I bought, not what I had prior, FWIW.)

IDK if the makers of this re-pop run out of Taiwan or off the mainland. I concur that there likely isn't more than ONE manufacturing source, thus my irritation with these people.
 
I WONDER about Spectra. Actually not sure if they're even fronting the 1966 Newport's unit. I certainly didn't find one in the 2 years I searched before settling on what I now have! Spectra makes EVERYTHING BUT a fuel sending unit for a 1966 Chrysler Newport.

I've seen a number of vendors for a unit like what I bought. I suspect the prior unit I had in my gas tank MAY have been a Spectra, of a sort not meant for '66 Newports. (I see in the 1966 catalog that the fuel sending unit, 14-72-1 looks like what I bought, not what I had prior, FWIW.)

IDK if the makers of this re-pop run out of Taiwan or off the mainland. I concur that there likely isn't more than ONE manufacturing source, thus my irritation with these people.
Just for laughs, I looked at the Spectra website and yes, they don't show a sender for a '66 Newport. BUT! I did find a listing for a '66 300, which I would assume would be the same as a Newport. I haven't double checked that in the Chrysler parts manual though, but I think it's a safe bet that the 300 (and other models) would share the same sender/gas tank/fuel gauge. FG143A is the part number.

Parts Results for This Vehicle

I've discovered that the listings for the old cars will sometimes need some creative interpretations. They will list something that they have good info that it fits and rather than take a chance on other models, they'll just omit the results. When you step back and think about it, it's probably wise.... Better to lose a little bit of low volume sales rather than annoy a couple customers that will do damage (through word of mouth, forums, etc.) to your reputation.

In fact, if you look at the listed applications for FG143A, you'll see that it's kind of a mish mash of what it fits. I'm sure it's low priority to refine the listings for Spectra and I understand it. Part of the hobby is dealing with this and passing the info on to others.

A couple things that I've observed though with other guys dealing with gas gauge problems and I'll bet your background can confirm this.

There is a lack of understanding how it works. The sender provides a resistance to ground and the gauge simply measures that resistance. No magic involved... With those absolute facts, you have the following areas where there could be failure of the gauge working and/or reading correctly.

First, and probably the most blamed (right or wrong) is the sender. It is an item that wears, no matter what happens. The wiper arm rubs against the coil and no matter what, it is going to wear. They weren't designed to last 50+ years.

Second is grounding to the sender. This seems to be very misunderstood. The factory added a small clip to provide ground to the sender via the fuel line. That was great when all was new, but again, 50+ years later, things like rust or the line being patched or replaced, I don't see as it's a reliable source of ground. A better ground would be to run a ground wire directly from the sender to the body. I've done this more than once with good, reliable results.

Third, and probably overlooked often, is the wiring from the sender to the gauge. It runs through a hole in the trunk floor, along the driver side floor and up into the dash. Another 50+ year old piece... If the insulation is broken, you have a direct path to ground with a resulting gas gauge that says "full". If the wire itself breaks down, either the gauge doesn't work at all or there may be added resistance in the wire that now makes the gauge read low. That simple fact is just not understood.

Fourth, you have to provide power to the gauge. Chrysler did a simple voltage "limiter" that works mechanically to provide 5 volts to the gauge. Another 50+ year old piece that is bound to fail. Good news is there are direct replacements that do this through the magic of half century old electronics and are very reliable and accurate.

Fifth, is the gauge itself. If you've ever taken one apart, this little gem of cheaply made junk will simply amaze you that most of them are still functioning. Chrysler had a purpose made tool that provided resistance to check these gauges. I have a eBay sourced, used decade box that works nicely to do this. Simply grounding the wire from the sending unit will show function, but not accuracy. Another misunderstood function.

I just read so many threads where understanding the function of the gauge is ignored and throwing parts at the problem is tried with utter failure and usually the sender gets the blame without even thinking about how everything needs to work together.

Edumacational rant off.
 
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Has anyone found a DECENT SOURCE OF SENDING UNITS? Mine, purchased 3 yrs ago, is crap, reading somewhere between 40-70 ohms, and consequently not much good can be made of it with a decent working gauge. I would like to get a somewhat better sending unit, if such can be had. I too am driving a 1966 Newport. Since my unit doesn't change value over most of the range of motion, I see little point in dropping $60+ for that nice interpolator made for GM sending units, but applicable to Mopars.
Got mine from a reputable ebay seller, 1965, works great, think it was $100, I can look it up if needed
 
Just for laughs, I looked at the Spectra website and yes, they don't show a sender for a '66 Newport. BUT! I did find a listing for a '66 300, which I would assume would be the same as a Newport. I haven't double checked that in the Chrysler parts manual though, but I think it's a safe bet that the 300 (and other models) would share the same sender/gas tank/fuel gauge. FG143A is the part number. .

Yes, I've seen the *143A, 5/16" units by Spectra and others for the past 4 yrs. They're not quite right. The OLD unit looked a lot like one of these. FWIW, but not like whats in the 1966 Mopar Parts Catalog. What I wound up buying does. I've found some likely candidates recently too. These DO NOT come from that *143A pattern.

Here is something that matches for 1966 Newports and the catalog:
CHCSND655.jpg


Van has done me right on other gas tank stuff, so I might use him for this, if I find nothing better. Note the brass float, unlike the plastic ones Spectra and others sell. Alas, what I GOT has a SWELL FLOAT, but the wiper coil leaves a lot to be desired! Be that as it may, this is the correct form factor for the 2 year period, 1965-1966. Things changed a little after that.


In fact, if you look at the listed applications for FG143A, you'll see that it's kind of a mish mash of what it fits. I'm sure it's low priority to refine the listings for Spectra and I understand it. Part of the hobby is dealing with this and passing the info on to others.

Thus my taking the trouble to include the pic above.
There is a lack of understanding how it works. The sender provides a resistance to ground and the gauge simply measures that resistance. No magic involved... With those absolute facts, you have the following areas where there could be failure of the gauge working and/or reading correctly.

First, and probably the most blamed (right or wrong) is the sender. It is an item that wears, no matter what happens. The wiper arm rubs against the coil and no matter what, it is going to wear. They weren't designed to last 50+ years..

(Snicker) YEsssss, many of today's crop from the universities haven't ever wound a coil or couldn't to save their own lives. Nichrome wire coil resistors, whether meant for fixed or variable use are pretty 19th century to start with, but these still serve for fuel sending units. Of course NO varnished wire is going to withstand 50+ years of motion from a little metal wiper, and with condensation in the tank, as well as moonshine, even well wound units were meant to last FIVE, not FIFTY FIVE years.


Second is grounding to the sender. This seems to be very misunderstood. The factory added a small clip to provide ground to the sender via the fuel line. That was great when all was new, but again, 50+ years later, things like rust or the line being patched or replaced, I don't see as it's a reliable source of ground. A better ground would be to run a ground wire directly from the sender to the body. I've done this more than once with good, reliable results.

This is exactly what I did. My #10 bonding jumpers ground numerous portions of Mathilda. Thus, she is electrically sound. The straps sold to folks pre-suppose that the REST of the fuel line is all conductive, which mine isn't, ergo, I grounded the unit to the body, which is jumpered nearby up to the engine block by a series of jumpers.

Third, and probably overlooked often, is the wiring from the sender to the gauge. It runs through a hole in the trunk floor, along the driver side floor and up into the dash. Another 50+ year old piece... If the insulation is broken, you have a direct path to ground with a resulting gas gauge that says "full". If the wire itself breaks down, either the gauge doesn't work at all or there may be added resistance in the wire that now makes the gauge read low. That simple fact is just not understood. .

Indeed! And blue #16 primary wire isn't that expensive to replace, and can be run in some nice tubing to protect it too, if the old stuff is not up to snuff. Amazingly enough, the stuff in mine is alright, as I checked it out. I also checked the sender before and after installing. Its range of resistance is buggered between ~20~55 ohms. Not the 10-70 Ma Par favored.

Fourth, you have to provide power to the gauge. Chrysler did a simple voltage "limiter" that works mechanically to provide 5 volts to the gauge. Another 50+ year old piece that is bound to fail. Good news is there are direct replacements that do this through the magic of half century old electronics and are very reliable and accurate. .

Yes, a crude thermo-electric point set that opened and closed on a duty cycle around 50%. I use a 5VDC solid state supply, though not the prescribed one for the instrument panel. Be that as it may, I thought it best to run 5V through the circuit, even though the after market gauge is rated for 12V. This will be upgraded as soon as I get a sender with the proper resistive range of 10-70 ohms.

Fifth, is the gauge itself. If you've ever taken one apart, this little gem of cheaply made junk will simply amaze you that most of them are still functioning. Chrysler had a purpose made tool that provided resistance to check these gauges. I have a eBay sourced, used decade box that works nicely to do this. Simply grounding the wire from the sending unit will show function, but not accuracy. Another misunderstood function.

I know. I inadvertently disassembled the original one as I removed the instrument panel. The reason so many still work is because most folks don't remove the instrument panel. I've got a replacement panel now, in better shape than the original, which I will eventually install, though I use my array of after market, NOS Stewart Warner and Clark Brothers gauges (except for the fuel gauge!) and will continue to use them. I want the old speedometer, fuel gauge and shift indicator back in service eventually, despite my preference for analog gauges. i MAY use that fellow who modernizes the old panels, if his work isn't too exorbitant.
 
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