The Stovebolt Site Forums The Shop Area The Electrical Bay Anyplace to buy a fuel gauge converted to 12v.

For a 1951 3100.
Jim Carter has some listed for earlier models. I contacted them and was told they are out of '47-'54 and don't have anymore windings to do the conversion.

I tried an aftermarket 12v but they don't work. The needle presses on a shaft rather than being bent like the original. The hub of the needle hits the face glass. I don't know how anybody is making those work. I also tried resistors (several types) but was not having much luck with accuracy.

Seeing that JC used to sell them I thought maybe someone else does, or could convert my original.

Hi Dave -

I bought the 12v fuel gauge for my '54 (converted to 12v) from The Truck Shop. The needle presses onto a shaft as you described. The gauge works OK. The needle on the reproduction gauge is flat instead of peaked down the center and the tip is more rounded than the original. None of the differences is noticible. I don't know of any aftermarket supplier that makes "bent needle" gauges like the original.
> CLICK - Truck Shop Fuel Gauges

The distance from the back of the dial to the front of the needle is a little greater than the original. Even though the gauge is thicker than the original, the needle does not rub on the glass or on the innner bezel of the cluster (although it is very close to the inner bezel and could rub in some installations.) It is slow to move to "F" when I fill up, but I don't think that it is caused by the needle rubbing on anything.

I tried to bend the dial a little to make it sit at the same level as the other gauges. Not successful in bending it / was afraid that I would break if I tried harder. When mounted, the dial does not look any closer to the inner bezel than the other gauges.

If you find a gauge that you like, you will still need to scuff and paint the dials and needles of all gauges and speedometer, then reface with decals available from most suppliers. Otherwise, the new gauge will not match the color or sheen of the old gauges.
> CLICK - '54 Refaced Gauges New gas and temp gauges.

Please let us know if you find a gauge with a bent needle like the original.

How much did JC ask for an original converted fuel gauge?
I didn't know they offered them

for those who are not aware of the problem here is a pic of the raised needle
...pic...


if you are stuck with using an aftermarket 12 fuel gauge try adjusting the bezel by gluing a gasket to the back of it
...pic...

...pic...
it will give you enough room to clear the raised needle.



original 6v are on ebay, you could purchase an nos and use a reducer with it.

You may be OK using the original gauge. I put over 100K on my old '55.1 panel after converting it to 12v & running the original 6v gas gauge at 12v. It never failed during that time.

I think about $90. Here was the email I received:

Dave,
We have run out of windings for the 12 volts so all we have now are aftermarkets.
Thank you,
Julie

So if I understand correctly, you were running the 6v gauge on 12v? Were you using the original sending unit or did you use a 12v? Did it read accurately?

I might give that a try. I've ruined one aftermarket gauge trying to modify it to fit. At the price they are I don't want to do that many more times.

Yeppers. Original sending unit. It's been a while but I believe the reading was a tiny bit different, the width of the needle, but I don't remember whether it read a tad higher or lower than before. Either way it wasn't an issue. When it read in the neighborhood of 1/8 tank it was time to visit the gas station.

Reviving this thread to see if there is any new/updated information on replacement gauges? I still have the original gauge in the truck for cosmetics, but it is not functional. It's the only non-functional item on the truck and I'd love to get it corrected this winter. Very frustrating when the parts companies say, "Manufactured to factory specifications....looks and functions like the original", when they clearly don't.

I used a 30 ohm 2 watt resistor on my gauge and it works correctly. That is the only value of resistance that works, if using a straight resistor.

Dave, Like Tiny, I too am running a stock 6 volt gauge with no resistor on my 12 volt truck. The truck and gauge are 1946 GMC. The gauge works fine with the stock sending unit (replacement bought from J.C.)

Dave

Well, the sending unit in the tank was new when I did the restoration. I see J.C. lists the same sending unit (30 ohm) regardless if it's 6 or 12 volts. I guess I'll just hook up the gauge and see what happens. If it kills the gauge I'm not out anything, but with 2 people saying it will work, I'm feeling pretty good. I'm trying to remember back to when I put everything together and I think I tried using a resistor without any luck. Fingers crossed. Thanks for the replies.

Please let us know if you fry the gauge.
If you do, maybe some members will help buy a new one, and a resistor.

If the gauge does or does not get fried, please let us know - for the consideration of future readers.

If you use this Runtz-style resistor, you will not fry the gauge.
Yes, $12 (delivered) is an expensive innsurance policy for an easy to replace gauge.

I have at least 10 1954/55st used gauge sets, and I do not know if they were only used with 6v, or if they might have been used with 12v. About half the fuel gauges do not work. This means nothing, really, but none of the other gauges have been unusable.

Tim,
It could be that my gauge was already bad, but I am fairly certain that I tried it with the runtz-resistor and it would not work with it. I don't remember if I checked the voltage out of the resistor. I probably still have the resistor and will go back to square 1 in trying to get the gauge functional. I know my original plan was to use an aftermarket 12v gauge and was dissapointed to find out it would not fit as original.
Thinking out loud here...I wonder if I used the 6 volt setting on my battery charger if I could test the gauge with it?

I just went out to try to figure this out. The sending unit is giving me 17 ohms. I guess that would be about 1/2 full which makes sense. But when looking at the back of the fuel gauge I've confused myself. The two terminals are both marked for the sender. Obviously, one of them is wrong. One has a red caution tag not to connect power. The other has the word "Sender" stamped onto a cardboard insulator. Back when I did the restoration it looks like I marked the housing with an "S" and "P" for power and sender. That matches the red caution tag. It's possible that I put the cardboard insulator on backwards when I installed it. Before I connect power I want to make sure it's correct. Currently, the wire from the sender is connected to the one with the caution tag. The other one has nothing connected. If someone know definitively which is which, or how to determine it, it would be appreciated. Here's a photo:

Old post/thread a this subject.
DADS50 image in that post/thread is attached below.

Tim,
Thanks. That picture would confirm that I have the sender wire on the correct post and probably put the insulator on backwards, not noticing it was stamped. I'm going to go put 6 volts on it from my battery charger and see what happens.

Dave,

Thanks goes to DADS50 - he always tries to post good/clear information and documentation.

The gauge posts have to be correctly wired for the gauge to read correctly. i.e. Input and a output
The sending unit should show with full tank of gas 30 ohms.
You can test just the gauge without the sending unit connected.
You can use the 6 volt charger to do the test.
Connect +6V to the gauge power terminal. Connect the battery negative or ground lead to the gauge mounting plate. At this point, the gauge needle should go to "full" or beyond. Now connect the gauge sender terminal to ground (or the mounting plate). The needle should go to "empty" or beyond.

If you get the above results on both the sending unit (30 ohms) and fuel gauge shows full with 6 volt applied and it still doesn't work.
Check for bad wire connections and a bad ground connections at sending unit.
If still no go check wire to sending unit..
1949-53 Shop Manual Fuel Gauge Testing
Sorry I don't have a KMO-204 gas gauge tester. But I would like to have one.

Tech Tips:Gas Gauge Problems

I still would use a Runtz-style resistor Gas Gauge Voltage Reducer.
That stuff was designed to be used with 6 volts

It appears I had multiple issues. First I pulled the "new" sending unit to check resistance. It showed a consistent 0-15 with the arm moving from empty to half, but then as I continued to raise it, it started showing very sporadic readings. What I found was the contact in the sending unit was not making positive contact in that range. I removed the cover and bent the contact tab and it now shows a very consistent 0-30 ohms as the arm moves from E to F. The picture shows the tab I had to bend. (Hope that info will help somebody with a bad sending unit.)

The gauge still wasn't working properly so I pulled it out to bench test. I connected 6v to the gauge and connected the sending unit. I grounded the sending unit, but not the gauge and with the sending unit in the empty position (0 ohms) the needle went to about 1/4 tank. As I raised the arm, increasing the ohms to 30, the needle dropped to E (backwards from what was expected). I then grounded both the gauge mount and the sending unit and the needle froze at just above E and would not move regardless of the sending unit position. Regardless of what I did, I could not get the gauge to go above 1/4. I can only deduce that the gauge is fried. This is disappointing because the face and needle are in mint condition.

Does anyone know of a place that will rebuild the gauge?

Thanks for all the help.

Did you do this:
Connect +6V to the gauge power terminal. Connect the battery negative or ground lead to the gauge mounting plate. At this point, the gauge needle should go to "full" or beyond. Now connect the gauge sender terminal to ground (or the mounting plate). The needle should go to "empty" or beyond.

If you did and it's still stuck you can replace just the gasoline gauge.
I doubt that anyone would rebuild the gasoline gauge.

The master parts catalog says:
Group # 3.108 Gauge
49-53 Commercial, Utility
54-55 FFC (Flat Face Cowl) Part # 1517169

Partsvoice says the below vendors each have one NOS in stock.

Nos Parts Source
Olathe, KS 66062
913-220-5746

Modern Chevrolet Company
WINSTON-SALEM, NC 27101
(888) 306-0825 ask for parts department

Collectors Auto Oroville Gm
Blaine, WA 98230
800-414-4462

There are couple on eBay also, punch in the part number.

Go HERE for 2nd opinion and pics

What color is your needle?

Here are some other Fuel Gauges 12 & 6 volt
The Filling Station
FUEL DASH GAUGE 12-Volt - White Needle Fits 1950-53 Chevrolet Truck and 1952-53 GMC Truck. Larger Pic
FUEL DASH GAUGE 6-Volt - White Needle Fits 1950-53 Chevrolet Truck and 1952-53 GMC Truck. Larger Pic
Note these gauges have 1516973 & 1516974 on the front face which are for 47-48 trucks. Check difference and fit before you purchase.

FUEL GAUGE RESISTOR - FOR 6 TO 12 VOLT CONVERSION Larger Pic

Be careful with the orientation of that "resistor" (attached image on the right) - if it is the correct Runtz-style reducer there is an input side and an output side.

The one sold by Classic Parts (in my post above) is made so that it cannot be mistakenly installed backwards (and it includes screw ends/fittings). (attached image on the left)

https://fifthaveinternetgarage.blogspot.com/2015/11/the-runtz-story_10.html

I had tried what you suggested and it would not go above 1/4 tank. I followed your suggestion for searching out a NOS gauge and picked one up on ebay for $50.00. The part number you listed is stamped on the face of my original gauge. $50.00 is cheaper than I was quoted to rebuild my original. I was hoping to have them convert it to 12v as part of the rebuild, but they recommended using a "buck converter", but they want $50.00 just for it. I think I'll go with the Runtz. It looks like people use the Buck converter for higher draw items like the heater blower.

Thanks for all the input.

Dave,

Like Tiny I ran my 1936 Chevy pickup with the original 6 volt gas gauge and sender for about 5 years and 50K miles as a 12 volt daily driver "rat rod" (V8 engine, B & M "Hydrostick" transmission, etc) in the 1960s with no problems. Now that same '36 is restored to original, including 6 volt electrics, and the same gauge and sender are still working fine back on 6 volts.

So the "converted" gauge seems to be a solution looking for a problem.

Got the NOS gauge installed including Runtz voltage reducer. I think I had multiple problems before. The original gauge was bad and the new sender was not working until I bent the internal tab as I mentioned earlier. All is good now! It'll be nice not having to worry about running out of gas. Working under the dash was a lot easier when I was in my 20's.

That truck is absolutely beautiful!

Wow ! That's the neatest rememberence of a fallen hero I have ever seen with an old classic truck .I have just stopped looking at it after many minutes ,,thx fallen heros dad for sharing,, I have shown this posting to my whole family and they and I want you to know that what you have done for your so is an act of love that no other could give him..

Wow, just Wow.

Wow! is right. Be sure to go to FallenHerosDad's signature line, click on the website for FallenHerosDreamRide.org and view the video. Extremely well done and you get to see all the artwork and understand what the images represent.

Dave, this is beautiful,
From another Dad,
Kent

Thanks everyone for the comments. Definitely was a labor of love. Have a Merry Christmas!