Sending unit ground strap on stainless

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like_A_pike

like_A_pike

that's not factory
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Im finally getting a new tank and lines swapped over to all stainless. I just bent the new sender to match the old one and tested both for resistance. This doesn't work if the meter isn't grounded. Then I remembered not seeing a ground on the old tank when I removed it. The insulator pad was shot so there was plenty of contact between the car and the tank. I figure this is how my gauge was still working. My questions are: how does that strap go on? "Fig 8" in the manual is just about useless. Is it bridging the fuel line around the rubber gas line? Anybody just use a bit of copper? Any trouble getting grounded with stainless lines? Thanks in advance. DW
 
Anything that will ground the sending unit to the chassis will work.

I think the bridging strap works due to the metal clamps that hold the fuel line to the chassis
 
In most cases the sending unit is isolated from the rest of the tank by a gasket. It wont matter how much grounding you do to the tank. There needs to be a ground connection at the sending unit mount (normally a clip attached to the output fuel line of the sending unit) and a clip making connection to the ground of the body of the vehicle (also, normally another clip around the fuel line attached to the vehicle). Between the two clips is a short wire of coarse, and the rubber hose that makes the connection from the tank to the fuel line. So this clips and wire are like a ground jumper. If that all makes sense.
 
Blind Squirrel said:
In most cases the sending unit is isolated from the rest of the tank by a gasket. It wont matter how much grounding you do to the tank.
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Yes and no. The gasket does isolate the back side of the sender from the tank but the lock ring contacts both the tank and sending unit on the front.
On mine I drilled a 1/4" hole on the corner of the tank. The aftermarket tanks usually have a flange with plenty of material OUTSIDE of the weld. From there I did a braided ground strap to the frame. The original grounding strap does not work well with sending units that have larger output line.
 
MoparMike1974 said:
Yes and no. The gasket does isolate the back side of the sender from the tank but the lock ring contacts both the tank and sending unit on the front.
On mine I drilled a 1/4" hole on the corner of the tank. The aftermarket tanks usually have a flange with plenty of material OUTSIDE of the weld. From there I did a braided ground strap to the frame. The original grounding strap does not work well with sending units that have larger output line.
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Absolutely agree "it should" but I would ask. Then why did the engineers find the need to fabricate the grounding device attached on each side of the rubber hose @ the metal fuel line. Contact should be complete some where in the mix with the tank straps to the body more efficiently than the flange ring. Heck just through the flow of fuel in the line should make a complete circuit. But then I just pulled a 16hr run again and no sleep maybe I'm missing something. I can learn.
 
Well the tank straps are not a good ground and the top of the tank had the pad on it. I chose to run a ground to the tank itself mainly because I have an in tank pump and wanted the extra safety factor. Either way I would not rely on the factory ground strap.
 
Dana67Dart said:
Have to disagree.... The lock ring is in direct contact with the sender and the tank.
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And again, if the engineers thought that was such a great ground. They would have eliminated the need for the 2 clip wire ground that they came up with. $.20 or .30 cents times how many million cars. Profit is profit.
 
I never put a lot of thought into why the lock ring to sender and tank, then tank contact to hanger straps wasn't sufficient chassis ground path for the fuel sender. The factory engineers discovered it wasn't, but my main reason for never pondering,,, a daisy chain of metal to metal contacts isn't a sufficient ground path anywhere. In a more perfect world the ground path back to batt' negative post would be a negative wire harness very similar to the positive wire harness.
For fuel sender without a proper fitting factory ground jumper, a length of wire secured under gear screw clamps serves the same.
 
I've never liked that grounding scheme. Don't know what your sender "is" but if it is a steel outlet tube, I'd be temped to solder a pigtail ground wire and run it to the body.
 
67Dart273 said:
I've never liked that grounding scheme. Don't know what your sender "is" but if it is a steel outlet tube, I'd be temped to solder a pigtail ground wire and run it to the body.
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I bought the stainless one from classic. It appears you have to use silver solder on stainless and I don't have any idea how conducive that is....
 
like_A_pike said:
I bought the stainless one from classic. It appears you have to use silver solder on stainless and I don't have any idea how conducive that is....
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Well what I read suggested silver with acid core flux and I know that you need the rosin core stuff for electric work
 
Are you saying the entire metallic structure of the sending unit is stainless? Then I don't know, other than some sort of clamp
 
Just clamp the ground wire directly to one of the sending unit tubes, using a hose clamp. Run the other end of the wire to the frame somewhere. No need to do any "iffy" soldering.
 
67Dart273 said:
Are you saying the entire metallic structure of the sending unit is stainless? Then I don't know, other than some sort of clamp
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Yeah, the catalog stated SS "throughout" it's certainly a fancy looking thing clamped in the vice next to the old one!
 
like_A_pike said:
Yeah, the catalog stated SS "throughout" it's certainly a fancy looking thing clamped in the vice next to the old one!
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You may already know that none of the replacement fuel senders are accurate. They'll show full and empty which is better than a dead sender. Good luck with it.
 
RedFish said:
You may already know that none of the replacement fuel senders are accurate. They'll show full and empty which is better than a dead sender. Good luck with it.
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Yeah, I've gone through a bunch of threads here on the subject and think I have a pretty good strategy... my gauge and sender weren't paired well to start with. I was empty when the gauge said 1/4 tank!!! One reason for the swap over. Anyway, my resistance range is much higher with the new one, I bent the pickup a skosh more, and if that fails, I'll buy one of those "meter match" do-dads! Foolproof No?
 
Can't trust the gas gauge in most vehicles anyways. What I did was starting with an empty tank, write down what the gauge reads. Add 2 gallons, write down what the gauge reads. Repeat about 7 more times, each time stopping to write down how many gallons are in the tank, and what the gauge reads. Now you have a pretty good reference for gallons vs gauge.

But I still just take the worst MPG I have seen and keep track of mileage. I get to about 120 miles on a full tank, I know I better fill it up pretty soon.
 
Blind Squirrel said:
And again, if the engineers thought that was such a great ground. They would have eliminated the need for the 2 clip wire ground that they came up with. $.20 or .30 cents times how many million cars. Profit is profit
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Agreeded.


The tank may or may not be grounded by its mounting.

But if the tank gets a dedicated ground on the exterior of the pinch weld to the chasse the sender mount clamp ring will provide the ground.
 
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