JMD

You almost certainly (like 99.9%) have a short circuit to ground or to +12V on the gauge to sending unit wire.

The old gauge likely didn't smoke because it was of better construction than the repro replacement.

Jon260

Well it looks like I need more help because I'm stumped on this one. I checked the voltage going to the fuel gauge and sure enough, it was 12v. So I built my own IVR as per the instructions here

http://chris66dad.tripod.com/id29.html

Today I installed the new IVR and had 5v going to the fuel gauge but it doesn't even twitch when I turn the key on. I then tried connecting the old fuel gauge to see if maybe the 12v completely fried the new one, but the old one has no response either. I'm not sure what is going on because now I have a new sending unit, new fuel gauge, new IVR, and 5v going to the input wire to the gauge. Can anyone give me any ideas what to do next? The only thing I'm thinking at this point is that maybe BOTH of the gauges are now bad, which would really be a bummer as I won't be able to spend the money on another one for quite awhile now. Thanks in advance!

(edit: I should also mention that I filled the tank up completely a while back but I did drive it quite a bit since then. I added about 1½ gallons last time I drove it just so I wasn't risking getting stuck. I'm fairly confident that there's anywhere between a few gallons to a quarter tank in there now. Even a few gallons would register on the gauge though right?)

Iskwezm

your in the same sutuation as me from about 5 years ago. I put white faced overlays on my gauges and didnt center my guage, so it smoke the IVR.I replaced it, no change.I can ground the wire at the sender and the guage and it would swing past full, meaning the guage is ok.I recently made a new IVR and get 5V at the guage.After poking around some more, im thinking my newish made in china sender is the problem.Im going to see if i have my old sender and meter it to see what ohms it should read full/empty.

Jon260

Do you think that it damaged your sending unit when your IVR was destroyed, or do you think that the sending unit was just bad out of the box? Is there somewhere where we can get a better constructed sending unit? Let me know how this works out for you if you don't mind, and thanks for the input.

Iskwezm

i know how i jacked mine up. When i reinstalled my guage, the post are not supposed to touch the metal casing and the fiber washers are there for a reason. When i turned the key, it smoked. Im going to check the wire from the guage to the sender for continuity to make sure it didnt break or whatever to make sure.

This has been a 5 year problem that finally pissed me off enough to look at to. I usually put in $20 everytime i take it out. So as soon as my tank is empty, i will pull the sender and meter it.

Stangatic

my 66 had the same issues, and it ended up in smoke just like what you had. It ended up being the voltage regulator on the back of the instrument panel. Not sure if your 64 1/5 has one, but you might want to check it with a voltmeter to see if it is working.

Jon260

Yeah I replaced the IVR recently.

crehder

I saw this on Youtube for checking the gas guage operation: