The Stovebolt Site Forums The Shop Area The Electrical Bay Fuel Gauge problem

Did I really BLOW 2 new fuel gauges????
Recently I replaced the gauge in my 12v 1955e. But I crossed the wires and by all accounts killed it. So...

I installed a 2nd new gauge this week and did this... Please Comment....

After testing new gauge, sender and wiring, I connected the ground wire from sender to gauge. Next, I connected the 12v source wire, BUT, upside down under my dash with my glasses slipping, I put the 12v wire on the SAME post for sender. (Note: no wire on the 12v post, 2 on the ground post!) Not knowing that, I turned the key to see if the needle moved. Nope. I quickly turned off the key and put the 12v wire on the proper post.
My gauge stays at 3/4.
Did I kill gauge number 2?
Any ideas?

Take out the gauge and bench test it again. If it works you have another problem - probably a bad ground. If it doesn't, you've ruined it.

Anyone have ideas for me excluding taking out the cluster and gauge again? After twice, I'm hoping to delay that until I'm certain that I'll need a 3rd gauge, and only then after resting my bones and my ego.

Thank you bolters.

Don, I apologize for posting on your post. I have cleaned up my mess and moved my errant posts to the correct spot. . But can’t fix the other replies. This will require admin help.

Thanks Darren. It seems like you're making good headway with your gauge issue. Good luck.

I'm getting nowhere, except for Otto's suggestion to remove the gauge and bench test it.

Does anyone have an idea to test or fix my fuel gauge in the dash? Or tell me if it's blown?

Wow, thanks Darren. I will remove my post also then, so this thread can move along without a big question mark of mine in there.

If the needle doesn’t move at all when you turn the ignition on, you will have to remove the gauge “again” and bench test as Otto suggested.

When you installed the gauge, did you check to see if the trim piece interfered with the needle?

Some of the reproduction gauges are made slightly thicker and the needle gets caught on the inner trim piece inhibiting the needles movement, making the gauge look like it’s not functioning. If you find this condition, a gentle push with your fingers will give you the additional clearance you need to keep it from binding. Mind you I do mean gentle as it moves easily and you don’t want to distort the inner trim piece.

I know what a pain it is to have to remove and disassemble the cluster as I had to do it three times myself before I got my gauge to function properly. To help with removing the cluster, I replaced my nuts with brass knurled nuts from the hardware store which makes them so much easier to remove and reinstall.

My new gauges came with a warning tag that "IF you short it out, it will be damaged".

Thanks Phak1.
I love your idea of the knurled nuts.
Removing the cluster again is depressing.
But, when I'm mentally ready, I'll do it again and double check the needle clearance as you suggest.

Rusty, as far as a "short", I'm not sure I shorted it if BOTH wires were on the sender post and NO WIRES on the other. Without power going THROUGH the gauge, could it short?

Thanks.

My limited understanding of a "short" is when a "hot" wire is connected to a "ground" wire, that is a short... did any smoke come out of the wires?

A year or so ago...maybe a year and a half...I posted titled "Your fuel gauge explained, sort of." Here is a link: https://tinyurl.com/mr32amap

On the back side of your fuel gauge, there is possibly a red tag. At least originally there was and it is important. Or maybe some prior owner labeled the two connections. On the back of one I used for study, etc I labeled it "red" and "fuel" to tell me the "fuel" side went off to the fuel sender unit. The red goes to the ignition switch. If you confuse the two, it is highly likely you will burn out your fuel gauge. In that post linked above, I try as much as possible to explain how the fuel gauge works...how it is a balanced magnetic scheme with two similar-looking but different electromagnets and how they both work to show you how much fuel you have. I explained this a week or so ago on another post. If you burned up your fuel gauge, you can repair it...that is if you are a very patient person. What must happen is you must separate the 2 electromagnets, buy two different gauges of magnet wire, unwrap the original coils, measure the length of each type of wire used and replace it, connecting the two as was originally done. What you have are 2 magnets, each wound with different wires so that they have different electromagnetic field properties. Sadly when an electromagnet is fried, there's not usually a good way to know where the boo-boo manifested itself...could have been easy to see, but usually is buried deep within the windings. Good luck. If questions, please let me know.

Nope. No smoke. No clicks or sounds.
Just the sense of disbelief over putting the power wire on top of the ground wire!

The short could been thru the internal ground. One terminal on the gauge is for the power and the other is for the signal from the sending unit. If you touched the signal wire, it will still short to ground.

Thanks for clarifying (the embarrassing bad news).

I'll report back in next few weeks after ordering & receiving another gauge.

Don

Don, if you haven't done so yet, please don't discard the old one. There is a chance I have the right gauge of wire to rewind it so there is a possibility it could be saved for another use. I wouldn't do that right now...I'd wait for a rainy day or a colder day when I'd have to work inside. I'd pay the postage, by the way.

Jon, that is a generous and kindhearted offer.
Rewinding that gauge seems like a precision undertaking, similar to building a ship in a bottle.
But,with your encouragement, I will give it a try.

I have TWO new 12v gauges that I've blown. Would parts from them be useful?

Don