new fuel sending unit ugh!

[straightjob]

Help! i just had a sending unit supplied by me, installed in my 68 300 vert, by a local mechanic , picked it up gauge red 1/2 full ; drove home and ran out of gas, (of course i did) filled it up and the needle is buried past the full line , he says its defective im calling BS , any suggestion?

 

[gyknot]

Realistically, if all he did is install a unit you provided, I don't see how he is at fault if it reads. Obviously it doesn't read correctly but since it changes with the amount of fuel you put in the tank, its not stuck or anything.
Did the old unit read at all?
With what little info I have on your issue, either the sending unit doesn't work right, or possibly there is a voltage issue causing it to read way too high. I don't know enough on the gauges to guess more than that.
My only other guess would be if the unit wasn't "clocked" correctly in the tank, but from what few I've changed, I don't believe its possible to get it in wrong and still get the unit to seal or the locknut to engage its thread to hold the unit in.

I'm curious what you find out on this. Fuel gauges are one of my most annoying issues.

 

[Ross Wooldridge]

If the float arm is not "calibrated" properly to the rheostrip of the gauge, it will read incorrectly. Symptoms include reading way past the full mark and not reading empty (float arm too low), or reading empty way too soon, and not reading full when the tank actually is full (arm too high).

In your case it sounds like the float arm is bent too far down - this will make the gauge read overfull when full and not empty when the tank actually is - because the float gets push too high, and can't get down far enough to indicate on the rheostrip the actual reading.

The fact that it's reading signal at all means that it's not defective necessarily, it's just not calibrated.

You may be able to bend the float arm up a little bit so that a full tank of gas does not read is high and empty reads empty. It's trial and error - I went through this with my station wagon many years ago and the mechanic at the radiator shop was able to calibrate it just by tweaking the angle of the arm.

 

[Big_John]

First, describe what was going on before you had the sender changed.

As I see it, there can be several things wrong.... First suspect is the new sender.

A lot of folks are now going to talk about grounding the sender and while that is important, since your gauge seems to be reading high, that would tell me there's not a ground problem. Also, since it's reading high, I suspect the wiring is good.

Next possible culprit is the voltage limiter located behind the dash. This gives 5 volts to the gauges to make them work correctly. I always suggest replacing these with a new electronic version.

Then there's the gauge. Usually not the problem, but it could be.

Ultimately, to get a correct reading gauge, you can install a Meter Match which will compensate for errors in the gauge/sender. Here's my experiences: Gas Gauge Fix

 

[volksworld]

oh boy. i just bought a questionable aftermarket part that i was too dumb/ lazy to install myself so obviously the mechanic is a thief/idiot

 

[straightjob]

Realistically, if all he did is install a unit you provided, I don't see how he is at fault if it reads. Obviously it doesn't read correctly but since it changes with the amount of fuel you put in the tank, its not stuck or anything.
Did the old unit read at all?
With what little info I have on your issue, either the sending unit doesn't work right, or possibly there is a voltage issue causing it to read way too high. I don't know enough on the gauges to guess more than that.
My only other guess would be if the unit wasn't "clocked" correctly in the tank, but from what few I've changed, I don't believe its possible to get it in wrong and still get the unit to seal or the locknut to engage its thread to hold the unit in.

I'm curious what you find out on this. Fuel gauges are one of my most annoying issues.

Thanks for the reply it was below Or on E the old unit was rusty I guess from sitting the unit was brand new could it be a regulator on in the dash I recall my ranchero had an issue it it solved the erratic reading?

 

[CBODY67]

Is the sender you supplied a "new replacement", "universal", NOS stock unit, or one that is supposed to work? BIG differences in the outcomes and what it should take to make each variation work.

Just some thoughts,
CBODY67

 

[1970FuryConv]

Thanks for the reply it was below Or on E the old unit was rusty I guess from sitting the unit was brand new could it be a regulator on in the dash I recall my ranchero had an issue it it solved the erratic reading?

I work on 1969-1973 c-bodies, but generally the voltage limiter also regulates the temperature gauge. Is that acting up as well?

I suspect the sending unit too.
For New sending unit, www.vansauto.com
For Rebuilders, you could check out www.hemmings.com

 

[Big_John]

I work on 1969-1973 c-bodies, but generally the voltage limiter also regulates the temperature gauge. Is that acting up as well?

I suspect the sending unit too.
For New sending unit, www.vansauto.com
For Rebuilders, you could check out www.hemmings.com

1968 Chrysler didn't have a temperature gauge, just "hot" and "cold" lights.

The voltage limiter only controls the gas gauge.

 

[straightjob]

Ok I just purchased one I’ll try that before dealing with the tank I ain’t getting any younger ! Vans doesn’t have one any other places the old one is toast

 

[straightjob]

oh boy. i just bought a questionable aftermarket part that i was too dumb/ lazy to install myself so obviously the mechanic is a thief/idiot

Wow what an ahole you don’t know my situation I’m in a wheel chair what a tool your parents must be proud

 

[straightjob]

1968 Chrysler didn't have a temperature gauge, just "hot" and "cold" lights.

The voltage limiter only controls the gas gauge.

Wow thanks the dash is a little easier for me to work with really appreciate it

 

[C Sickness]

I replaced the tank sender along with the tank. Re-did grounds.Reads "1/2" with a full tank. Most of the time it's 1/4 to empty, even though there's gas there.

I just bought a new voltage limiter. How much of a headache is it to change it, what's involved?

 

[CBODY67]

I suspect that if you got a new sender, unless it looks exactly like the orig sender, it will need some tweaking to get it to read right, rather than the Meter Match mechanism, per se. Meaning that, although it was sold with your particular application fuel tank, the sender is more "will fit" than "accurate for the application fit".

Just my suspicion . . .
CBODY67

 

[Ripinator]

oh boy. i just bought a questionable aftermarket part that i was too dumb/ lazy to install myself so obviously the mechanic is a thief/idiot

Hey Beatle Boy: Where are you coming from with a comment like that?!? Everybody here is learning as we go. If you can't help, please keep quiet and learn along with the rest of us.

 

[Ripinator]

I suspect that if you got a new sender, unless it looks exactly like the orig sender, it will need some tweaking to get it to read right, rather than the Meter Match mechanism, per se. Meaning that, although it was sold with your particular application fuel tank, the sender is more "will fit" than "accurate for the application fit".

Just my suspicion . . .
CBODY67

Yes. This is true. I don't know of any currently available senders that read accurately. I think they are all manufactured for a "universal" fit and function. Of course, this means they universally fit nothing and universally malfunction. For my part, I recently purchased the Meter Match unit described in Big John's thread. One more thing: Most of the senders are Chinesium, but there is one supplier who has USA-made senders: Quirey Quality Design ( Phone: (814) 509-6410 )

 

[Big_John]

I replaced the tank sender along with the tank. Re-did grounds.Reads "1/2" with a full tank. Most of the time it's 1/4 to empty, even though there's gas there.

I just bought a new voltage limiter. How much of a headache is it to change it, what's involved?

Depends on a couple things.

If that's for the '70 300 in your pic, there's 2 possibilities. If you don't have a low fuel warning light, it's on the back of the dash cluster. Hard part is getting to it.

If you have the warning light, it's part of the low fuel relay near the right side ash tray. With the low fuel relay, the voltage limiter isn't going to be a "plug and play" and the aftermarket limiter won't work with it.

I had the warning light and wanted to keep it, so I incorporated a Meter Match with their optional low fuel warning light, a relay (to light the light) and a cheap voltage limiter to make the drop to 5 volts, but as said, it's not "plug and play". I believe you should be able to remove the low fuel relay and use the dash "plug in", but you'll lose the low fuel warning.

 

[Big_John]

Yes. This is true. I don't know of any currently available senders that read accurately. I think they are all manufactured for a "universal" fit and function. Of course, this means they universally fit nothing and universally malfunction. For my part, I recently purchased the Meter Match unit described in Big John's thread. One more thing: Most of the senders are Chinesium, but there is one supplier who has USA-made senders: Quirey Quality Design ( Phone: (814) 509-6410 )

If Quirey is selling a USA made piece, with presumably better quality, they need to get up on the roof and start yelling that.

 

[Ripinator]

If Quirey is selling a USA made piece, with presumably better quality, they need to get up on the roof and start yelling that.

John: I just found out about the sender while talking with Dave Quirey at the Greenville, SC 300 Club Meet. He said he gets them from the original US manufacturer.

 

[volksworld]

sorry guys...must have needed snickers last night...as a shop owner/ mechanic for over 45 years i lose my cool when i hear anyone automatically blame the mechanic...and believe me there are PLENTY of incompetent and dishonest mechanics out there...and there are PLENTY of bad aftermarket replacement products too...and i certainly had no idea the OP couldnt work on his own car...maybe leading with that would have prevented me from putting my foot in my mouth....considering most of the suggestions given were also things he couldn't do himself i doubt anyone else was aware of the situation...so once again sorry...but for future reference, if you walk into a shop with your own part and say ''install this" that's all you are going to get...and when it doesnt work they'll probably blame the part....IF they are a competent shop and you ask them to troubleshoot and fix the problem they will...at a much greater cost....the majority of us are on here because we cant find anyone out there that has a clue that we can afford to pay, that's why we do this stuff ourselves....i cant even imagine owning a vintage car and having to rely on someone else to fix it....unless i was Jay Leno...ps cant ask my parents if they're proud because they're dead but thanks for asking