Rumrunner
Well-Known Member
Yes, there is fuel in the tank.
Fuel Gauge
- Thread starter Rumrunner
- Start date
Rumrunner
Well-Known Member
I have tested the SU in and out of the tank, moved the float and nothing. I don't really understand the getting voltage to the SU when it's a ground return. I understand that all positive have to have a negative return to work but when I first started working on this issue the fact that from the SU it's a ground return kinda confused me. And still does!
You shouldn't have 12 volts at the sender, it should be a pulsing 5 volts via the Limiter on the back of the cluster. You need the ground to complete the circuit. The gauge works by the resistance to ground thru the sending changing.
Russ69Runner
Well-Known Member
Have you tried a new gauge? You said the old one worked when testing it right. Something is fishy here. Do you have a wiring diagram? Take a couple of days away from it and start fresh this might help you out.
Rumrunner
Well-Known Member
Measured it this morning. 5volts, jumping between just above 4 and just below 6.
Rumrunner
Well-Known Member
A little progress. I now have two SU on hand. Hooked up the old one (third one) out of the tank, checked the ohms 75.5-9.1 And it made the gauge move to the empty position, put the new one on, (fourth one) and the gauge moved to 1/4 full. As Russ has said as well as Carl, sounds like I've been getting crap senders.
Is there anyone out there who knows a vender who sell's quality Sending Units?
Is there anyone out there who knows a vender who sell's quality Sending Units?
Rapid Transit
Just A Traveler In Time
You may already know.
Just a suggestion since you have your fingers in the system already.
I'm assuming you still have the old voltage limiter in the dash cluster.
Once you get it straightened out, I would suggest changing to one of these to protect your gage in future.
https://www.rt-eng.com/index.php/RTE_limiter.html
IVR4 would be for you.
Just a suggestion since you have your fingers in the system already.
I'm assuming you still have the old voltage limiter in the dash cluster.
Once you get it straightened out, I would suggest changing to one of these to protect your gage in future.
https://www.rt-eng.com/index.php/RTE_limiter.html
IVR4 would be for you.
Rumrunner
Well-Known Member
At the gauge, the two sending units floats were set at full for the readings above and dropped to below E when lowered.
I had no idea there was a alternative in voltage limiters. I briefed through the advertisement above and will spend more time looking into it. It certainly sounds like the way to go. Thanks for the heads-up.
Is there anyone out there who knows a vender who sell's quality Sending Units?
I had no idea there was a alternative in voltage limiters. I briefed through the advertisement above and will spend more time looking into it. It certainly sounds like the way to go. Thanks for the heads-up.
Is there anyone out there who knows a vender who sell's quality Sending Units?
Rumrunner
Well-Known Member
Reading more of the articles for a RTE limiter and For $50, It seems like a no brainer. Also looked up the cost for the old ones and
the price seemed to range from $43-$78. However I already have two that are working.
I had thought when a voltage limiter went out things just stopped working. these articles state that everything in the dash could fry.
I also don't get how on the RTE limiter how an LED light would be seen?
the price seemed to range from $43-$78. However I already have two that are working.
I had thought when a voltage limiter went out things just stopped working. these articles state that everything in the dash could fry.
I also don't get how on the RTE limiter how an LED light would be seen?
Rapid Transit
Just A Traveler In Time
The big thing is that the old ones can go bad and fry your gauge.
They may never go bad, but if it does you gauge gets 12 volts and "fries with that".
The gauge pegs out full scale and goes poof in a few seconds.
LED.
Page 2, number 5
https://www.rt-eng.com/images/a/ad/LimiterManualIVR4_c.pdf
They may never go bad, but if it does you gauge gets 12 volts and "fries with that".
The gauge pegs out full scale and goes poof in a few seconds.
LED.
Page 2, number 5
https://www.rt-eng.com/images/a/ad/LimiterManualIVR4_c.pdf
69hemibeep
Sponge Bob Square Wheels
If I'm reading this correctly when you connect the sending unit outside of the tank and swing the float up and down you get good readings? If so your ground source is the problem to the tank if they dont work in the tank . And no there are no good sending units in the after market I adjust them to where I know empty is empty and full can be high or low depending on the unit and tank shape. My runner shows over full when full and my Valiant is slightly below full but I know empty is empty
69hemibeep
Sponge Bob Square Wheels
Oh I do suggest the RTE limiter. One volt can cause up to a 1/4 tank loss at the gauge
Russ69Runner
Well-Known Member
I fill up when the gauge reads a quarter of a tank, just to be on the safe side. LOL. I don't like walking.
Rapid Transit
Just A Traveler In Time
OP may know already but many people complain about the ring not sealing.
I've never had a problem with that and suspect some other issue.
For example I just had to "tweek" a new one from Classic.
(Not to be confused with twerk)
The sock hit the bottom of the tank and made the flange just a little cocked.
I could have forced it.
UT has a new video about fuel problems.
Spoiler!
I bought a 86 Diplomat years ago that had that charcoal problem.
Soon as I put gas down carb it started so I bought it for 600 dollar from the car charity.
Found charcoal in the electric QJet.
Spoiler 2!
I had to buy filler hoses twice for a first Gen Charger.
First set went bad in 3 years.
Chinese rubber???
IDK but I've had that dry rot issue with Chinese air hose from Harbor Fright.
Got 40 year old American hoses that are still good.
I've never had a problem with that and suspect some other issue.
For example I just had to "tweek" a new one from Classic.
(Not to be confused with twerk)
The sock hit the bottom of the tank and made the flange just a little cocked.
I could have forced it.
UT has a new video about fuel problems.
Spoiler!
I bought a 86 Diplomat years ago that had that charcoal problem.
Soon as I put gas down carb it started so I bought it for 600 dollar from the car charity.
Found charcoal in the electric QJet.
Spoiler 2!
I had to buy filler hoses twice for a first Gen Charger.
First set went bad in 3 years.
Chinese rubber???
IDK but I've had that dry rot issue with Chinese air hose from Harbor Fright.
Got 40 year old American hoses that are still good.
Rapid Transit
Just A Traveler In Time
That's rule number 3 of "Ways to tell you are driving a MOPAR."
"Listening for fuel sloshing to know how much is in it."
Rumrunner
Well-Known Member
I ordered the RTE limiter this morning. I adjusted the float past the stop and got this gauge to show full.
Of course by now I've beat the s--- out of this sending unit and am ordering a new one. Again.
And my wife does not like walking either!
Of course by now I've beat the s--- out of this sending unit and am ordering a new one. Again.
And my wife does not like walking either!
Russ69Runner
Well-Known Member
After putting 2 and half inch recurve spring on my runner had pic up problems. Had the same thing with a 73 charger after putting on air shocks to raise the car at rear. So, bent the pic up tube to the right in the tank and had a loss of fuel when car was sitting low on the right side when pulling off road. Had to rethink the problem so pulled the sending unit and adjusted the pic up tube too center of front in tank and closer to being flat on the bottom. Only had to tweak the float arm a bit to get the right reading at gauge. Everyone says the after-market tanks are not the same as the one came with car. Now the age-old problem with air vent lines spewing fuel out of them. The one that runs up into the trunk and into the frame rail. It let fuel poor out the frame rail in front of passenger rear tire. Put a small nipple in the filler tube just below the gas cap and ran a rubber flex line from it and behind the bumper. Ran it over one side of the gas tank and up to the shock tower. Still watching to see if that is the fix for the flooded vent lines. Hope you finaly get things sorted out on your car and can get it out and about. 
Rumrunner
Well-Known Member
Got the newest sending unit and RTE Limiter. Testing out of the car w/jumper wire from sending unit wire to where wire hooks up to SU and ground from battery to SU. and new limiter installed, The gauge would not move, bent the float full stop out of the way, bent the float arm and gauge would register 3/4 full and drop to below E when I would move the float from full to 3/4. Thought maybe, the needles on my gauges might be dragging so I removed the dash cluster, took it apart and made sure the needles weren't dragging. adjusted the needles slightly
(if you haven't messed with the needles they are very, very delicate) So now when i have the SU float set to full, the gauge reads full, but when I move the float to 3/4 the tank shows below empty.
It's nice to know when the tanks full but would like to know when I might be close to running out of gas.
(if you haven't messed with the needles they are very, very delicate) So now when i have the SU float set to full, the gauge reads full, but when I move the float to 3/4 the tank shows below empty.
It's nice to know when the tanks full but would like to know when I might be close to running out of gas.