gas gauge sending unit 330 GT 2+2

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GEODAVKY
Posts: 97
Joined: Wed Nov 21, 2007 9:40 pm

Re: gas gauge sending unit 330 GT 2+2

Post by GEODAVKY »

The sending unit is out of the tank and testing with the ohm meter by moving the float arm up and down I’m getting good ohm readings but it is intermittent. It will give readings 4 or 5 times then no readings.
1967 330 GT 2+2 8767
George Davidson
John Vardanian
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Location: San Francisco Area

Re: gas gauge sending unit 330 GT 2+2

Post by John Vardanian »

Put the unit in a steady hold (like a vice), connect your meter, then sweep the arm very slowly from one end to another--the way it would move inside the tank. From empty to full it should range about 20 to 100 ohms.

john
PF Coupe
GEODAVKY
Posts: 97
Joined: Wed Nov 21, 2007 9:40 pm

Re: gas gauge sending unit 330 GT 2+2

Post by GEODAVKY »

John thanks for all of your help. I can’t see anything visually that might be wrong-no broken wires etc. An estimate to repair was somewhere between $200 and $400. I’m checking around for a replacement now, but unless theses units were used in a Fiat I’m not hopeful on a better replacement price.
1967 330 GT 2+2 8767
George Davidson
John Vardanian
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Location: San Francisco Area

Re: gas gauge sending unit 330 GT 2+2

Post by John Vardanian »

George, you might be able to get a cheaper replacement, but you have to retrofit the float arm. The other thing is make sure that the replacement has a warning light terminal.

john
PF Coupe
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330GT
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Re: gas gauge sending unit 330 GT 2+2

Post by 330GT »

GEODAVKY wrote: Sat Jul 18, 2020 10:45 am John thanks for all of your help. I can’t see anything visually that might be wrong-no broken wires etc. An estimate to repair was somewhere between $200 and $400. I’m checking around for a replacement now, but unless theses units were used in a Fiat I’m not hopeful on a better replacement price.
I doubt that a Fiat would have such a tall tank.

I fixed the sender in my PF Coupe. Make sure that the sliding portion makes good contact. Then carefully, using fine wet/dry sandpaper (600 or higher), sand the wire surfaces where the sliding portion contacts. This removes any corrosion and should make for an even contact. Then follow John's recommendation to make sure that the ohm readings are consistently moving up or down as you move the float arm. You can also attach it to the wiring and be able to watch the fuel gauge as you move the arm.
The float design is different on your 330, but see http://www.parrotbyte.com/kbc/ferrari/P ... elTank.htm for what I did.
Regards, Kerry
http://www.330gt.com 330 GT Registry
http://www.parrotbyte.com/kbc/ferrari 250 PF Coupe 1643GT, 330 GT 2+2 8755GT, 308 GTS 23605
angrywilson
Posts: 3
Joined: Mon Aug 07, 2017 6:28 pm

Re: gas gauge sending unit 330 GT 2+2

Post by angrywilson »

I have been trying to repair my sending unit and gauge by following along with these posts and what I found so far is that my 330 is running 20-300 ohms full to empty. The sending unit is working correctly my gauge is showing full regardless. I am curious if anyone knows what the little tab (center bottom) in the picture is for. It looks like maybe is was attached to the main structure at one point but even if it was there is that black material everywhere that would appear to act as an insulator. Not sure what the point would be. Anyway I may be grasping at straws hoping there is any easy fix to my always full problem. Maybe my car is just an optimist.
Thanks
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angrywilson
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Re: gas gauge sending unit 330 GT 2+2

Post by angrywilson »

I have an update. I put the system back together again and now my gauge does show a slight change. Basically it fluctuates between full and a 3/4 full as you move the sender between empty and full. I double checked the sender and it is still operating between 6 and 300 ohms.
Jimmyr
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Re: gas gauge sending unit 330 GT 2+2

Post by Jimmyr »

George,

Sounds like you now have the correct ohms and readings on the sender that you need, and as said above earlier, try to again make proper grounding to the sender. Connect a jumper wire from any of the 6 mounting screws to a good ground like the frame or seat belt bolt. These gauges are quite simple in design, but their connections have a lot to be desired; especially on aged vehicles! Jim
John Vardanian
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Re: gas gauge sending unit 330 GT 2+2

Post by John Vardanian »

I had the very same problem when I reassembled my dash. The fuel gauge would peg all the way to the right as soon as it powered up. My problem was the two wires were swapped. Did you make this same mistake? You may look into the sending unit about the 3/4 full issue.

john
PF Coupe
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