Gas gauge

[The_architect]

Boinkster I thought you did pretty well with the drawing. One thing I've noticed, those early gauges can be expensive--they are delicate things, with that copper wire being thinner than a human hair. Mine was messed up and I had it rebuilt rather than buying one of unknown quality off of ebay.

I agree with Kim about the gauge and sender needing to be calibrated to each other. These are not precisely made components. I think my new sender put out about 80 ohms as opposed to 70, but that's close enough.

I bought my sender new. It took me a second try before I got one that worked--so do measure the resistance with an ohmmeter before you mount it in your car.

You can temporarily set up the gauge an a sender with a 12V power supply to see if they work. It takes very little current to make them go. I set the whole thing up on the bench and calibrated them before I mounted the sender in the gas tank or the gauge in the dash.

Another thing that I did was replace the new sender's plastic float with a brass one like this: brass fuel sender float since there are reports of the plastic ones leaking. These seem to be a universal size. The ebay one I have listed seems to be a bit on the pricey side. Shop around.

Charlie

 

[regularman]

Of the plastic ones that have leaked, that I have seen, there was a hole in one end where the piece was made and it was very thin and temp or altitude change made it blow out. It can be fixed with a soldering iron, melting the plastic on that end down so it puts a thick seal here (after getting any liquid out of course)

 

[regularman]

On the senders, the new ones are not the quality of the old ones. I have had to remove windings from them to get them in the ballpark resistance wise. Someone sent me a new one and their old one. The old one just needed the wiper bent after it was taken apart because it was lifting off the wire at the very top when full due to play. I got it calibrated to the gauge and then removed windings from the new one to make it work. It was around 110 ohms and should have been 70. That was a pain because the ends of that resistor wire are not soldered but kind of pinched in there to make contact. I am thinking it was for the guy that had the Tunebug out in Colorado. I am not very good with names, I am afraid.

 

[The_architect]

I think you mean Drew in Utah. Good on ya for fixing that new one up, Kim. In my case when the float started banging on the top of the tank it was about 70 plus or minus. Good enough for goverment work as they say.

I also grounded my sender to the body through a dedicated ground wire as opposed to relying on the sender-to-tank-to body ground concept. I ground everything with dedicated wires, rear light fixtures especially.

 

[regularman]

I think you mean Drew in Utah. Good on ya for fixing that new one up, Kim. In my case when the float started banging on the top of the tank it was about 70 plus or minus. Good enough for goverment work as they say.

I also grounded my sender to the body through a dedicated ground wire as opposed to relying on the sender-to-tank-to body ground concept. I ground everything with dedicated wires, rear light fixtures especially.

Yes, that is the guy. Was it Utah? I was thinking it was Colorado. Don't know why. He talked about mountains quite a bit, maybe that is what made me think of CO.