New fuel gauge needle falls to 4 o'clock position

[Bandit130]

Recently purchased new fuel gauge (approximately 2 weeks ago). Worked perfect till this morning and needle was pointing to 4 o'clock position. This has only happened today. After starting, gauge moves back to the level I remember it being before turning off. Old gauge was working, just bouncing.

Has anyone had this happen with their gauges? Or, do I possibly have a defective gauge which I can possibly exchange.

[44SAA]

You may wanna check your trans fluid. When mine is low, my needle becomes erratic

Edit- apologies as I misread your post. My speedo gets squirrelly when atf is low

[mongocanfly]

/\/\/\("You may wanna check your trans fluid. When mine is low, my needle becomes erratic ")/\/\/\
curious...what has the trans fluid level got to do with the fuel gauge?

more than likely your issue is a wiring problem or ground issue

[44SAA]

Good catch Mongo- I mistakenly thought OP was having issues w speedo. Apologies for the confusion

[mongocanfly]

haha...no sweat...I thought you was gonna learn me sumpin new

[WorkinLonghorn]

"4 o'clock position" you mean pegged past the full area? That usually means an open circuit in that wire from the sender to the gauge (if it's anything like a 67-72). I've never had a '74. I would follow that wire and see what's up. Maybe a '74 is totally different, but it seems like a good start.

[Dead Parrot]

Square gauges are similar to the earlier ones. Open = 3'oclock.

Not unusual for a gas gauge to wander once the power is off. As long as it returns to reading properly once power is back, don't worry about it.

[hatzie]

Originally Posted by Dead Parrot

Square gauges are similar to the earlier ones. Open = 3'oclock.

Not unusual for a gas gauge to wander once the power is off. As long as it returns to reading properly once power is back, don't worry about it.

^^This.
The original gauges had some damping that would slow the needle movement with power off when they were new. The damping got less and less effective as they aged. I doubt the aftermarket gauges are mechanically damped in any way.
As long as they read correctly when power is applied there isn't a problem that's easily remedied.
If it bothers you there are antique automobile gauge repair guys that can inject a special damping Gel into the core of the gauge to slow the needle movement. I remember reading about it on the C3 Corvette boards. The gel looses its' effectiveness over time just like the original damping.

[Bandit130]

Originally Posted by WorkinLonghorn

"4 o'clock position" you mean pegged past the full area? That usually means an open circuit in that wire from the sender to the gauge (if it's anything like a 67-72). I've never had a '74. I would follow that wire and see what's up. Maybe a '74 is totally different, but it seems like a good start.

With tank at current level of approximately 7/8 full, with key off falls to the right to the 4 o'clock position. Slowly falls and takes about 20 minutes to reach 4 o'clock. This has happened suddenly since install 2 weeks ago. Was not falling before. Clips were burnished before new gauge install. I had burnished old gauge and clips last year too. The old gauge did not fall when key off. (It was bouncing and would read correct after stop when gas movement slowed in tank). Nothing has been changed in the past 2 weeks, other than new gauge. I could tell new gauge had damping compared to old one. Needle did not bounce around.

[hatzie]

If it's reading properly with power applied and not bouncing around... it's working fine. That's the new gauges rest behaviour. Don't worry about it.

The needle is held in place by an electromagnetic field induced in the coils when power is applied. Once you remove power from those coils there's no or almost no magnetic field. This leaves the needle free floating and it'll kinda just do it's own thing. 20 minutes to drop to a full rest position means the damping is working properly.

[Bandit130]

UPDATE

Removed new gauge, reinstalled old gauge and works just like it did before installing new one. It does not fall at all with key off. Stays in same position as with key on. It still does bounce but is working. I noticed when I removed new one and placed it in the box, needle slowly fell to 4 o"clock.

New gauge did not fall till after 2 weeks.

Going to contact seller about replacement or return and refund. Will see.

[Bandit130]

Contacted seller, explained situation. Got response 2 days later they will send out new gauge and I could dispose of defective unit. I will hold on to gauge cause tested with needle at or below half tank and it did not fall below e with key off. It is still usable and will probably wait till someone needs another one and explain about needle falling. Waiting for new gauge to arrive in a few days.

[Bandit130]

Sorry...forgot to update.

Nope...Another new gauge, sent for free and still have first purchased one, when near full falls to around 4 o'clock and sometimes to 6 o'clock position. When near empty, falls to 4 or 6 o' clock position when key off. Always when key on, needle moves to correct position. I have modified one of them with pins below e and below f so that needle does not fall more than that. It was bugging me when it fell so far. The pins are much better for me now. I also painted them flat black and do not show very much at all. You can see the pins I installed in pic. I now have an extra new gauge that I have not modified. The modified one is in truck now and will stay. This may be a common thing with aftermarket gauges, it is with the 2 I have. Gauge does not bounce around like the old one. Does move slightly while driving/turning but is a lot better.