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Re: Reed Style Fuel Level Sender

Posted: Wed Aug 25, 2021 8:47 am
by 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 :lol: :lol: 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. :doh: :doh:

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.

Re: Reed Style Fuel Level Sender

Posted: Wed Aug 25, 2021 12:13 pm
by 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?

Re: Reed Style Fuel Level Sender

Posted: Wed Aug 25, 2021 2:57 pm
by 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

Re: Reed Style Fuel Level Sender

Posted: Thu Aug 26, 2021 10:51 am
by plateaucal
Johnny Roadkill wrote: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.

Re: Reed Style Fuel Level Sender

Posted: Tue Sep 07, 2021 10:36 am
by moore_rb
Justin-

You can count me in for one...

Re: Reed Style Fuel Level Sender

Posted: Thu Sep 30, 2021 11:01 am
by rdarnell
not sure if I need one but at that price (70ish?) I am game. put me down for one.

Richard

Re: Reed Style Fuel Level Sender

Posted: Thu Dec 30, 2021 8:16 am
by 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

Re: Reed Style Fuel Level Sender

Posted: Thu Dec 30, 2021 9:25 am
by RiverPatrol
No. A resistor works differently than a regulator.

Re: Reed Style Fuel Level Sender

Posted: Thu Dec 30, 2021 12:08 pm
by 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

Re: Reed Style Fuel Level Sender

Posted: Thu Dec 30, 2021 1:17 pm
by desertrat
Slackd wrote: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.