The Stovebolt Site Forums The Shop Area The Electrical Bay Gas gauge update

My gauge started to act erratic, bouncing around when it should have been just under half tank. I filled my truck, and it went to over the full mark, that never happened before. SO, I pulled one bed board and removed the sending unit. I checked out the sending unit on the bench. It is 0 ohms at empty and 30 ohms at full. I replaced the wire from the gauge to the sending unit so I could route it better like the original wire was. It is 16ga and I soldered the connectors and put heat shrink on it. I have a ground to the sending unit already. All back in place but the gauge still read over full. SO, I disconnected the sending wire from the back of the gauge and turned it on. No response. I have read the tech tip about the fuel gauge diagnosis procedure. Well, after I powered it up without the sending wire attached, I could not see the needle. SO, I went out to the garage today to look at it again an tested my sending wire at the gauge end and it is good. After messing around trying to get the gauge to respond to something I found that the needle is GONE, MISSING, LOL. I shined a flashlight into the gauge cluster, and it is nowhere to be seen. This was a brand-new gauge cluster that has about 900 miles on it. I did not mis wire it or any such thing trying to get it to work again, mostly just using my ohm meter to check things, like gauge cluster ground and voltage to the gauge. Funny, the gauge is actually broken inside. I did hit a bad bump in the road just before the fuel gauge went bonky. New one on order already. I have an old one that seems to work, so, I might just hook it up outside the gauge cluster and see.


Well, I thought I would post my findings instead of adding to the other post. I took an old gas gauge that I had and hooked it up to the sender wire in my dash, then I put a jumper from my fuse block to the gauge, and a ground jumper on it too. I turned on the key and it read correctly as far as I can tell. My 47 3600 has the in frame 16 gallon tank that came with the truck. I have about 45 miles on it since the last fill. At 14.5 mpg it should be just above 3/4 tank, and it was. I'll have to drain the engine and disconnect the temp gauge and remove the gauge cluster on Monday.

I switched the fuel gauge out today. Here is a picture of the new gauge that failed. The needle was pointing down when I took it out, no wonder I could not see it. Can it be repaired by someone or is it junk?

Does the needle move? I wouod try just turning it back to face up, then plug it in and see what it does.

It will go 360 degrees without any hesitation. The old one that I installed only rotates 90 degrees. It has two coils in it. This new one looks totally different, almost looks like an electric motor inside.

It should have had internal stops to keep it centered-ish between the field coils. I wonder if the shaft came loose or something.

I would say there is a moderate chance of it being fixable. I sent you a PM.

I’ll look it over real good tomorrow. I wanted to get my dash back together today so I did not spend too much time looking at this gauge. I installed the complete gauge cluster new from the Filling Station. They had them in stock during the Covid episode. It is 12 volt. I had about 900 miles on the truck when it went bonky. I hope my old original gauge stays working. It is quite a bit to disconnect and remove the whole gauge cluster.

Is there any way you can show what it looks like on the back side? That looks ok from what I can see. There must be an hourglass shaped piece of magnetized metal for the thing to ever work...this is what the two different strength electromagnets will work with to show fuel level. I can't see how this one was built but it doesn't look quite like an exact copy.

Here are pictures of this new fuel gauge. That black triangle does not move. The needle will go 360 by rotating the gauge.

Thanks very much. That is completely different from the original. With these images this unit seems almost (not completely) to imitate a stepper motor. You mentioned you still had your original fuel gauge and that it was working. While more simple it is a very good design. Was the reason you chose the new one appearance?

I bought a complete gauge cluster because my temp gauge had a broken capillary tube. During covid I could not buy just a temp gauge, nobody had them in-stock. So, I opted to get it all new rather than rebuilding my old gauge cluster. They had complete gauge clusters in-stock. I rebuilt my speedometer and all the switches except the light switch, it had a broken dimmer.

Hmmm, okay. So you have a new complete gauge cluster. While you have it apart, if your old fuel gauge still works I was going to say I could send you a stick-on face for it which would make the old face look new. But...that is an odd shade of brown and what I've made might not match what you have. My natural tendency would be to remove the face plate from the new gauge however that entire gauge is not like the original. The little motor-thing seems to be spot welded to the plate, doesn't it?

Or here's another thought. Go to the "Interiors" forum section and look at the very top. There's a post (sticky) of the gauge decals I made (printable). You could print this page, see how close to the right color it was, amend it using Microsoft Paint 3D or other photo editing software and make your own face plate. You can either print these onto waterslide decal paper or you can have somebody with a good color laser printer print them to a sheet of regular coated paper and then apply a layer of double-sided adhesive. Once you cut out the fuel piece, apply it to the adhesive carefully and then remove the second backing paper, lick the adhesive side (your saliva will retard stickiness to let you align/adjust it) and then let it dry for several hours. Once your saliva is all dry, press gently down on the new "face cover" and it will stick like new.

Thanks, I had already bought a gauge decal kit when I restored the speedometer. That sheet had a fuel gauge decal on it, so I used that on my old gauge.