AUTOMETER fuel gauge

[stepinwolf]

Has anyone installed an Autometer fuel gauge, by splicing it into an original mid year Corvette harness.

I have just completed the wiring, and although I have the correct 90 ohm gauge, when it's hooked up as per manfacturers instructions, the needle swings to the wrong side.

When empty it has more then a full RH deflection, and when the tank is full, the needle goes to the LH or empty side. The terminals on the original gas tank harness are of a different size, so I am hesitant to reverse the connectors.

This is the first time I install the Autometer gauges, and was wondering if this was a common occurence.

Any comments on your own installation, would be welcome

Stepinwolf

 

[Hib Halverson]

I'd consult the gauge's instructions for the telephone number for Auto Meter tech. support. Maybe they can help.

 

[JohnZ]

I'd talk to AutoMeter and see if that gauge is designed for the midyear Corvette fuel gauge sending unit circuitry; the midyear Corvette was the only car on the planet that used a 3-wire powered voltage-divider sending unit instead of the ordinary simple 2-wire resistance-only sending unit that every other GM car used. The diagram below shows the unique midyear gauge and powered sending unit (which wasn't used after 1967).

 

[BADBIRDCAGE]

Has anyone installed an Autometer fuel gauge, by splicing it into an original mid year Corvette harness.

I have just completed the wiring, and although I have the correct 90 ohm gauge, when it's hooked up as per manfacturers instructions, the needle swings to the wrong side.

When empty it has more then a full RH deflection, and when the tank is full, the needle goes to the LH or empty side. The terminals on the original gas tank harness are of a different size, so I am hesitant to reverse the connectors.

This is the first time I install the Autometer gauges, and was wondering if this was a common occurence.

Any comments on your own installation, would be welcome

Stepinwolf

Hi Bob:

Your gauge is doing the exact same thing as my Autometer fuel gauge. I haven't put power to the sender yet on the original + terminal. I have the gauge connected to the S terminal and I have the ground securely grounded to the chassis.

I'm running a Painless harness.

1CoolC2 is running the same gauge setup as we are, he is feeding the gauge from the S terminal of the sending unit and his gauge reads properly. He says he does not have power to the sending unit.

I read the FAQ section on the Autometer site and it said to power the GM factory unit in the usual manner (on the + terminal) and hook the gauge to the S terminal. I need to get off my butt and hook up power to the sending unit to see if it changes things.

I will let you know what I figure out. (If I figure out anything)

Rich

 

[stepinwolf]

Gauge Update

Rich, listen up here's the latest.

I disconnected the power ( + Pink + ) to the sender, ( but I still have 12 volts to the gauge through the regular harness ) and the needle immediately returned correctly to empty, or left side of the gauge, which is good

Now as a concequense, every time the igition is turned on, the needle immediately swings to the right-most position, passed full, which is bad, since the tank is almost empty.

Then when the S terminal on the gauge is connected to the sender, the needle slowly goes to the empty position as I increase the float as per a full tank, which is also bad.

I have tried to get the Autometer people on the phone, but they have chosen to not published their number anywhere.

If you come up with anything, please let me know

Stepinwolf

 

[stepinwolf]

Here's the only solution

Here is, direct from the horse mouth, the only way you can use an Autometer fuel gauge, on 63 to 67 Corvettes. You will need to purchase, or replace the 90 ohm Autometer gauge that you have, and modify the original sender with one of their units. Here is what I have just received from their tech support.

'63 to '67 Corvette Fuel Level​

A typical 0 to 90 ohm or 0 to 30 ohm fuel level gauge will not operate with the stock Corvette fuel sender. The easiest way to use an after market gauge with this application is to modify the stock sender with components from the Auto Meter # 3262 sender and use a gauge compatible with 240 ohms empty and 33 ohms full. Below is the instructions to help you accomplish this. Remember, you need a 240/33 ohm gauge and a model # 3262 sender to properly complete this and to make it work.

• 1. Run your own, new wire from the "S" terminal of the gauge, back to the sender. Stranded 18g automotive wire will be sufficient.
  2. Drain the fuel tank and completely remove the original sender from the tank.
  3. Inspect the original fuel sender. You will see folded over metal tabs that hold the actual sender portion (the rheostat where the float arm pivots) together. Unbend these tabs and remove the cover. The cover will have a flat, copper strap that goes up to the head of the sending unit assembly. Remove the retaining nut from the top of the sender assembly, which holds this strap. Turn the strap and cover counter clock-wise to remove. You will no longer need this part.
  4. There will be a black wire attached to the float arm. Clip this wire at the float arm, but you may leave the wire in place, running down the length of the sender. You will use it later.
  5. To remove the float, remove the retaining that holds the float to the float arm. Remove the float, then you may start feeding the float arm back through the plate that the rheostat cover was attached to. Save this arm. You will need it later to design the new arm on the #3262 sender.
  6. Obtain the #3262 sender assembly and remove the white rheostat portion by removing the two Phillips head screws. Before removal, mark which location is up before removal.
  7. Remove the wiring stud from the top of the new sender, (note the order in which the nuts and washers come off!) but leave it attached to the new rheostat. Save the nuts and various washers. You will need these later.
  8. Test fit the new white plastic rheostat to the plate where the old original unit used to mount to and mark you location for the holes. Make sure that the new sender will be mounted so that the top is facing the up when the sender is re-installed in the bottom of the tank later. Drill & tap new holes to match the thread size of the supplied screws that you removed earlier from the white rheostat.
  9. Slide the large sending unit o-ring onto the sending unit at this time, up toward the mounting flange of the sender assembly.
  10. Mount the new rheostat to the sender assembly with the two previously removed screws.
  11. Cut the existing wire ring terminal off of the rheostat black wire. Strip the end of the wire and solder to the black wire that you previously left running down the length of the sender assembly.
  12. Install the new wiring stud on the white wire of the new rheostat through the existing hole in the top of the sender assembly. You may want to use a fuel resistant epoxy to help seal against future leaks. Use the same nuts, washers, and rubber seal that you previously removed. It is now a good idea to neatly secure the wires to the tube of the sender assembly.
  13. You will now carefully bend and trim the new float arm to match the original float arm. Take your time with this step to get it right.
  14. Attach the new float arm to the new rheostat.
  15. Lubricate the o-ring seal and begin gently, carefully inserting the assembly into the fuel tank.
  16. Once locked in place and install, fill the tank and check for leaks.
  17. Hook the new sender wire from your gauge to the new sender terminal on the sending unit assembly. Connect a grounded wire from the old sender terminal to chassis ground.
  18. Your new gauge and newly modified sender should work fine now together.

Hope this helps

Stepinwolf

 

[JohnZ]

I used AutoMeter gauges in my Grand Sport, but I never had to work through this issue with the stock sender, as I used an aftermarket foam-filled Jaz fuel cell with a top-loaded AutoMeter enclosed sending unit made specifically for that application.

 

[BADBIRDCAGE]

Thanks Bob

I just replaced the sending unit in my tank due to other issues. I can't currently find the words to properly describe how much I am looking forward to doing this again.

Rich