Moparts
B Body Fuel Sending Unit
Posted By: dobie
B Body Fuel Sending Unit - 04/19/10 06:16 PM
In searching things on the web yesterday, I found out that Right Stuff Detailing now has fuel tank sending units. I currently have their steel brake lines installed, and I've been very happy with them, and their company.
Obviously, my current sending unit isn't worth a crap, as it's way off, like everyone else's. It was bought new from Herb's Parts a few years ago. I just installed it last year, and it reads empty all the time. Grounds are good, as I even installed another ground wire to eliminate that problem.
Anyways, I called Right Stuff this morning and chatted with their tech guys. Of course, their's is imported as well, but no specific manufacture info could be provided. I had hoped for American made, thinking that finally someone will produce one that will actually work.
Anyways, does anyone here have one of the Right Stuff's sending units? I'm hoping for a good/bad/indifferent review of actual experience with one.
Thanks!
Posted By: Lefty
Re: B Body Fuel Sending Unit - 04/19/10 07:19 PM
Quote:
I just installed it last year, and it reads empty all the time.
Something else is wrong. I've never seen senders be more than 1/4 tank off the correct reading. Check the ohms, it should read between 10-90 ohms.
Posted By: mopar mike
Re: B Body Fuel Sending Unit - 04/19/10 07:36 PM
if the ground was bad, i beleive it should be reading way past full?? you could have a grounded wire to the sender??
Posted By: dobie
Re: B Body Fuel Sending Unit - 04/19/10 07:51 PM
Quote:
Quote:
I just installed it last year, and it reads empty all the time.
Something else is wrong. I've never seen senders be more than 1/4 tank off the correct reading. Check the ohms, it should read between 10-90 ohms.
What else would be wrong then? With all of the posts here and on other boards, it appeared that most new aftermarket sending units read incorrectly. The first one I had in the tank was off too. I don't know any of the history on that one, but it's safe to say that it wasn't the original one.
As far as checking ohms, I have no clue how to do that. I have a cheapie Craftsman multimeter, but have no clue on what setting I should be using, or where to test things. I'm a complete newbie and idiot on checking electrical things.
Posted By: dobie
Re: B Body Fuel Sending Unit - 04/19/10 07:55 PM
Quote:
if the ground was bad, i beleive it should be reading way past full?? you could have a grounded wire to the sender??
I have a reproduction part sending unit ground strap installed. It runs from the nipple on the sender to the metal fuel line. It's the metal band with the 2 alligator type clips on both ends. I've tried taking it off, connecting it on other areas, it all makes no difference whether one is installed or not. All of my other factory gauges work fine. I've never tested the gauge itself, but with it being installed in the dash, there's no way I'm pulling it out just to test it at this point. If that's the case, I guess I'll just live with it for awhile.
Posted By: 1_WILD_RT
Re: B Body Fuel Sending Unit - 04/19/10 08:07 PM
To test the gauge go to any electronics supply even Radio Shack may be able to help.. Get a 75 Ohm resistor & a 10 ohm resistor.. Together you should spend considerably less than $5.00
Connect the 10 ohm resistor to the wire going to the sending unit.. Ground the other end of the resistor.. Turn the ignition on, the gauge should read full... Now try the 75 ohm resistor, the gauge should read empty...
If it passes both these tests look for a shop (like Instrument Specialties) to rewind your original Sending Unit...
Posted By: dobie
Re: B Body Fuel Sending Unit - 04/19/10 08:31 PM
Quote:
Quote:
I just installed it last year, and it reads empty all the time.
Something else is wrong. I've never seen senders be more than 1/4 tank off the correct reading. Check the ohms, it should read between 10-90 ohms.
This is the multimeter I have. Obviously I'd use the ohms stuff, but what setting do I set the dial at, and where should the leads be placed on the car/sending unit?
http://www.sears.com/shc/s/p_10153_12605_03482141000P?keyword=multimeter
Posted By: Y3 70 BEE
Re: B Body Fuel Sending Unit - 04/19/10 09:06 PM
Last summer I did a comparison of a old factory 5/16 unit and the nowhere near accurate 3/8 Spectra that was in the car. I installed the old 5/16 and drove around and the gauge was working correctly. So I put the Spectra back in till this weekend when I performed surgery. I took note of where the float should sit then I cut the Spectra sending unit off the pick up with a hacksaw and the same to the factory pick up and cut the wire and or strap. Then I took 2 small gear type hose clamps and trimmed the sides so they would slid thru the slots in the factory sending unit and attached the factory sending unit to the Spectra pick up and connected them with the hose clamps and connected the factory type wire to the Spectra strap. No welding or soldering you will have to adjust where you clamp it together so the sending unit sits properly. Make sure the sending unit wire where you crimp them together does not touch the pick up anywhere and that the hose clamps are positioned so you can get the pick up in the tank. I only have one pic of where I cut the Spectra off at.
Posted By: Lefty
Re: B Body Fuel Sending Unit - 04/19/10 09:13 PM
Quote:
Quote:
Quote:
I just installed it last year, and it reads empty all the time.
Something else is wrong. I've never seen senders be more than 1/4 tank off the correct reading. Check the ohms, it should read between 10-90 ohms.
This is the multimeter I have. Obviously I'd use the ohms stuff, but what setting do I set the dial at, and where should the leads be placed on the car/sending unit?
http://www.sears.com/shc/s/p_10153_12605_03482141000P?keyword=multimeter
Set it on the 200 ohms scale. Test the meter by touching the two test leads together and make sure you're seeing less than 1.00 ohm. If that test passes, put one lead on the body of the sender and one lead on the terminal you connect the wire that goes to the gauge. With the sender arm at each end of it's operating range you should see the 10-90 ohm sweep on the meter. 
Posted By: dobie
Re: B Body Fuel Sending Unit - 04/19/10 11:14 PM
Thanks for the help! The sender is in the tank of course, and I was kinda hoping not to remove it, yet again... Oh well.
Posted By: 1_WILD_RT
Re: B Body Fuel Sending Unit - 04/20/10 01:40 AM
Well then.. Try this to pinpoint the problem...
Quote:
To test the gauge go to any electronics supply even Radio Shack may be able to help.. Get a 75 Ohm resistor & a 10 ohm resistor.. Together you should spend considerably less than $5.00
Connect the 10 ohm resistor to the wire going to the sending unit.. Ground the other end of the resistor.. Turn the ignition on, the gauge should read full... Now try the 75 ohm resistor, the gauge should read empty...
If it passes both these tests look for a shop (like Instrument Specialties) to rewind your original Sending Unit...
Posted By: dobie
Re: B Body Fuel Sending Unit - 04/20/10 01:46 AM
I certainly will. I plan on going to Radio Shack in the morning.
Thanks!
Posted By: Y3 70 BEE
Re: B Body Fuel Sending Unit - 04/20/10 01:54 AM
I don t no who makes a accurate sending unit I think the ones Dixie Restoration parts sell may be the real deal. Definitely check out everything before you throw parts at it.
Posted By: stinger
Re: B Body Fuel Sending Unit - 04/20/10 03:03 AM
maybe to much resistance in the factory wire?if the sending unit tests good before installation then what?
Posted By: Y3 70 BEE
Re: B Body Fuel Sending Unit - 04/20/10 03:15 AM
What I cant answer is that both the original and Spectra both were in spec at empty and full according to the factory manual using a ohmmeter. All I know is the old mopar sending works correctly and the Spectra never was even close.
Posted By: stinger
Re: B Body Fuel Sending Unit - 04/20/10 03:32 AM
this seems to be a common problem that everyone has with these after market senders.I remember reading somewhere that someone ran new wire from the sender to gauge and that solved the problem.larger gauge new wire should have less resistance in it then the old wire.I have a new aftermarket sending unit that I have not installed yet and been thinking about this for awhile now.
Posted By: therocks
Re: B Body Fuel Sending Unit - 04/20/10 12:21 PM
Mopars go empty when no ground.Hook a long ground wire to batt and to the sender wire.Turn on key and see if gauge goes full.If not you have a problem with power to sender or bad gauge.Rocky
Posted By: dobie
Re: B Body Fuel Sending Unit - 04/20/10 02:50 PM
Ok, the car is jacked up on stands now. Went to Radio Shack this morning and got a 10 ohm resistor. Looks like I'd need to solder it though. No clue on how to accomplish that. Right now, the easiest seems to be the ground wire Rocky suggested. I got that ready to go and will update accordingly. I only have about 7-10 gallons in the tank right now, so I'm wondering if that matters when I try the ground wire. Or, maybe grounding as suggested somehow overrides things and will cause the gauge to go to full..??
One thing I might add, the gauge seems to work, somewhat. On a full tank the needle goes to 1/2 tank, then drops quickly to empty. Never really seen it go much over 1/2 tank. Not sure what that might indicate.
Posted By: therocks
Re: B Body Fuel Sending Unit - 04/20/10 03:32 PM
Take the power off the sender attach the ground from batt.Turn on key and gauge should peg.Just dont leave it on too long.Rocky
Posted By: dobie
Re: B Body Fuel Sending Unit - 04/20/10 04:22 PM
No Sir, the needle didn't move one bit.
Just to make sure, hook one side to the positive terminal and the other to the sending unit itself, or the blue wire going to the sending unit?
Posted By: 1_WILD_RT
Re: B Body Fuel Sending Unit - 04/20/10 05:40 PM
The blue wire goes to ground not power... The reason you only want to do this briefly is there is no 10 ohm resistor so if you leave the key on it will smoke the gauge...
To ise the resistors a couple wires with alligator clips works well...
Posted By: therocks
Re: B Body Fuel Sending Unit - 04/20/10 05:43 PM
Just hook a test light to the hot wire at the sender.It should nlink.If it dosent either the V limiter is bad or break in the wire to the sender.Rocky
Posted By: dobie
Re: B Body Fuel Sending Unit - 04/20/10 08:05 PM
Well, thanks guys for all of the help. I basically give up though. Nothing I try works, so with my luck, it's the gauge itself. At this point, I refuse to tear everything apart to replace the fuel gauge. The easiest thing to do is to try another sender, but it's a crap shoot at best. Plus, once I buy it and install it, it's mine, and I have no need for another sender at this point. Besides, I always seem to spill about 2 gallons of gas trying to take it out. My little siphon that I have is terrible, and I can never get enough gas out before removing the sender. Therefore, I give up! Besides, the car runs fine, and it's nice to take it for a little spin when I want too, and not have things torn apart. Later this year I'll buy a 2 5/8 fuel gauge from Summit, slap it in, and hopefully fix (or bypass) the original problem. My car's a driver, so I'm not going for originality.
Posted By: dobie
Re: B Body Fuel Sending Unit - 04/21/10 01:52 AM
Ok, I got pissed again, and had to do something. I jerked out the sending unit and tried it out of the tank. Sure enough, when the float arm is all the way up, the gauge only reads 1/2.
Tomorrow I'll be trying another sending unit, so I should know tomorrow if it's either the gauge or the sender.
Posted By: Y3 70 BEE
Re: B Body Fuel Sending Unit - 04/21/10 01:57 AM
Check out the sending unit from Dixie restoration products the price is good and it made by the same vendor that made them for Chrysler.
www.dixierestorationparts.com
Posted By: 440challenger
Re: B Body Fuel Sending Unit - 04/21/10 02:01 AM
Had a problem like that. Ended up being the gauge. cant you ground the sending unit wire and see if the gaue reads full to make sure the gauge works?
Posted By: dobie
Re: B Body Fuel Sending Unit - 04/21/10 02:14 AM
Quote:
Had a problem like that. Ended up being the gauge. cant you ground the sending unit wire and see if the gaue reads full to make sure the gauge works?
Believe me, I'll be the first to admit, I'm an idiot in these matters. I tried that earlier and never could get the needle to move one bit. Even following the advice here, I couldn't get it. I figured pulling the whole darn thing out was my only option.
Posted By: Hemiruss
Re: B Body Fuel Sending Unit - 04/21/10 02:18 AM
Posted By: dobie
Re: B Body Fuel Sending Unit - 04/21/10 02:26 AM
That's interesting. I'll have to try that with a helper in the morning.
Posted By: Hemiruss
Re: B Body Fuel Sending Unit - 04/21/10 02:35 AM
Posted By: dobie
Re: B Body Fuel Sending Unit - 04/21/10 09:58 PM
I tried another sending unit this morning. Sure enough, both senders read the same on the gauge. At full stop, the gauge was only 3/4, then it would drop drastically. At 3/4 on the sender the gauge was at below 1/2 already. 1/2 on the sender was between E and 1/4. So, I'm of the opinion now that it's for sure the gauge.
That said, I went to Summit earlier and picked up an Auto Meter fuel gauge and plan to install it Friday morning. I'm definitely not spending 3 hrs to rip out my dash and go from there.
Posted By: pushbutton
Re: B Body Fuel Sending Unit - 04/22/10 12:03 AM
That said, I went to Summit earlier and picked up an Auto Meter fuel gauge and plan to install it Friday morning. I'm definitely not spending 3 hrs to rip out my dash and go from there.
Hope you have better luck than I did. I tried the exact same thing and my Auto Meter gauge read same as dash gauge. Just trying to live with the dash gauge for now. Been watching this thread as my problem sounds exactly like yours. Again good luck,sure wish I could get mine reading correct.
Posted By: 1_WILD_RT
Re: B Body Fuel Sending Unit - 04/22/10 12:12 AM
Posted By: dobie
Re: B Body Fuel Sending Unit - 04/22/10 02:57 AM
Quote:
That said, I went to Summit earlier and picked up an Auto Meter fuel gauge and plan to install it Friday morning. I'm definitely not spending 3 hrs to rip out my dash and go from there.
Hope you have better luck than I did. I tried the exact same thing and my Auto Meter gauge read same as dash gauge. Just trying to live with the dash gauge for now. Been watching this thread as my problem sounds exactly like yours. Again good luck,sure wish I could get mine reading correct.
You're kidding?? Great. My luck too I'm sure.
Posted By: dobie
Re: B Body Fuel Sending Unit - 04/23/10 06:50 PM
New fuel gauge is in, and nothing solved.
I give up.
Thanks for the help though guys.
Posted By: PAINT IT BLACK
Re: B Body Fuel Sending Unit - 04/23/10 08:15 PM
Quote:
New fuel gauge is in, and nothing solved.
I give up.
Thanks for the help though guys.
No offense, but I don't understand your mentality. If you let something like a silly sending unit beat you so easily, I can't imagine what other things in life have passed you by. Get out there, grab it by the horns and FIX THAT CAR!
Posted By: WilliamHall
Re: B Body Fuel Sending Unit - 04/25/10 08:09 AM
Ok, I just got my Sending unit and it didnt work like it should so I decided to take it apart and see what is wrong with it. First I had to bend back the three tabs that hold the sending unit together.
Posted By: WilliamHall
Re: B Body Fuel Sending Unit - 04/25/10 08:11 AM
You can see the resistor portion which a flexible copper tab rides against as the floating arm moves. Here is a picture of the resistor portion which is partially colored yellow. I am sure each little section equates to 1 ohm or so.
Posted By: WilliamHall
Re: B Body Fuel Sending Unit - 04/25/10 08:15 AM
And finally the solution. Just bend the copper tab back so that it makes a harder contact whith resistor part as the swinging float moves.
Then put it back together and rebend the 3 metal tabs. Hope this helps.
Posted By: charger RTSE
Re: B Body Fuel Sending Unit - 04/25/10 11:57 AM
I adjusted mine and got it nearly perfect.
The trick was to bend the float arm where it comes out of the sender so that when the float is fully up it will actually go up further on the mechanism inside do not bend the float arm on the end. I also bent the top stop back so to give the arm more travel.I hope this makes sence i took mine in and out three times before i worked out how to get it right.My original guage used to read over full. The new one reads just under full when i put the repro one in it first read 3/4 full.If i took it out again i could probably get it spot on.
Posted By: dobie
Re: B Body Fuel Sending Unit - 04/25/10 12:14 PM
Quote:
Quote:
New fuel gauge is in, and nothing solved.
I give up.
Thanks for the help though guys.
No offense, but I don't understand your mentality. If you let something like a silly sending unit beat you so easily, I can't imagine what other things in life have passed you by. Get out there, grab it by the horns and FIX THAT CAR!
So when are you getting here in Ohio? Seems like you're willing to help in person. Thanks!
Posted By: dobie
Re: B Body Fuel Sending Unit - 04/25/10 12:21 PM
Before I put the sender in, I tried it with the gauge. There was a huge dead spot. The float arm was 3/4 up when the gauge finally read anything, but at least it did go all the way to full. My factory gauge never did that. Right now I have about 14-17 gallons in it, and the needle barely comes off of E. Clearly, it's not the gauge, as it now appears to be the sending unit.
For now I guess I'll just burn through this tank of gas. No sense in draining out a full tank. Once empty again, I'll try working on the sending unit itself.
Posted By: WilliamHall
Re: B Body Fuel Sending Unit - 04/25/10 03:56 PM
Dobie, mine did the exact same thing(huge dead spot). The reason there is a dead spot is that the copper tab I pictured above is not making enough contact with the varying resistor. The solution is to bend the copper tab up so that it makes a harder contact.
Posted By: dobie
Re: B Body Fuel Sending Unit - 04/25/10 05:23 PM
I'll definitely try that. Any reason though why it worked better out of the car vs. installed in the tank?
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