Reed Style Fuel Level Sender

[jwgreen]

WOW!!!!!

I step away for one day to move my mom and there's a whole page of info!!!!

There's a lot of electrical jargon and technical speak being thrown around on this thread so let me ask a simple question,,,

I can have the senders made in whatever ohm range is needed, I chose the 10-100 ohms because it hit both style numbers, So is there a better range that would suit both gauges better or is the 10-100 range the best to work with? I was hoping that there wouldn't be any need to add resistors and such with this new one.

Also, thank you to everyone who are contributing to this thread with technical information. I know very little about electricity and your input is invaluable and much appreciated.

[plateaucal]

In theory (weasel words), if you made the device to be 10 - 90 ohms then someone could just put a 10 ohm resistor in series to make a 20 - 100 range. It seems sensible, but I wish I had a wiring diagram for the older style. Any other opinions out there from electronics specialists?

[Johnny Roadkill]

Agreed, based on the data given - a 10/90 range would replace the older style sender exactly and require a simple 10 ohm series resistor to suit the newer style.

If you went 20/100 it would replace the newer style exactly but if replacing an older style sender a 910 ohm resistor in parallel would make full read right but the gauge would read ~10% fuel left when the tank is dry.

One other thing that should be considered is the power rating of resistors used - without measuring actual voltages in system, I'd recommend the 10 ohm series resistor should be rated at 5 watts minimum or it may burn out when the tank is near empty. Larger value resistors in parallel like 910 ohm can be 0.5 watt types.

Cheers,
D

[plateaucal]

Agreed, based on the data given - a 10/90 range would replace the older style sender exactly and require a simple 10 ohm series resistor to suit the newer style.

If you went 20/100 it would replace the newer style exactly but if replacing an older style sender a 910 ohm resistor in parallel would make full read right but the gauge would read ~10% fuel left when the tank is dry.

One other thing that should be considered is the power rating of resistors used - without measuring actual voltages in system, I'd recommend the 10 ohm series resistor should be rated at 5 watts minimum or it may burn out when the tank is near empty. Larger value resistors in parallel like 910 ohm can be 0.5 watt types.

Cheers,
D

I would say Mr. Ohm agrees; 5 watts. Place the resistor under the dash to prevent weather impact.

[moore_rb]

Justin-

You can count me in for one...

[rdarnell]

not sure if I need one but at that price (70ish?) I am game. put me down for one.

Richard

[Slackd]

As a new Patrol owner, in an effort to clean up under dash wiring, I tossed(!) my gauge regulator, not knowing its purpose. Just now figuring that out. My temp and fuel gauge function but read way hot.

Reading through this post, if I purchase and reinstall a 10 ohm 5 watt resistor I’m back in business? Like photo attached.

Thanks
Dave

[RiverPatrol]

No. A resistor works differently than a regulator.

[Slackd]

Thanks. I figured that would be too easy. My punishment for throwing out a key part without understanding it’s purpose.

So, any idea where I can buy ye olde gauge regulator?

Also, River, I’m the one looking for a Rochester B carb insulator. Any luck finding a NOS in your vast store of parts?

Thanks. As always.
Dave

[desertrat]

Thanks. I figured that would be too easy. My punishment for throwing out a key part without understanding it’s purpose.

So, any idea where I can buy ye olde gauge regulator?

Also, River, I’m the one looking for a Rochester B carb insulator. Any luck finding a NOS in your vast store of parts?

Thanks. As always.
Dave

Not sure of any new old style (electro-mechanical) replacements available. I wrote a piece that's a sticky in electrical that explains the gauge systems. They run on 8 volts instead of the more popular 5 volts so there aren't really any swaps available.

If you do a search in the Datsun community, i.e. 1200, you will find a great many homebrew regulators ideas using various solid state components. There is at least one Datsun car parts supplier that offers a solid state unit for a pretty penny.