ConcoursMustang Forums

Restoring - General discussions that span across many different groups of years and models => Processes, Products & Techniques => Topic started by: orgnl70 on August 25, 2012, 09:50:36 AM

Title: Low Fuel Sending Unit
Post by: orgnl70 on August 25, 2012, 09:50:36 AM

Has anyone have a line on restoration of a low fuel  sending unit? Thank you

Title: Re: Low Fuel Sending Unit
Post by: ruppstang on August 25, 2012, 10:17:23 AM

I repaired the one in our 67 GTA. Most often the diode fails and it is just a matter of replacing it. NPD has them part #9A275-1  it is listed as a 67-68 part. I have not worked on the latter models and do not know if this part will work for them. You did not say what year you are working on. Does your fuel gage read properly? This will only fix the low fuel light. Marty

Title: Re: Low Fuel Sending Unit
Post by: midlife on August 25, 2012, 10:08:10 PM

Diode?  Don't you mean the thermistor in the fuel tank?  It's a device that changes resistance when saturated and dry.

Title: Re: Low Fuel Sending Unit
Post by: ruppstang on August 26, 2012, 12:20:35 AM

Yes Randy you are so right. I so not use those terms every day in home building :)

Title: Re: Low Fuel Sending Unit
Post by: midlife on August 26, 2012, 10:42:48 PM

I don't think diodes were even invented or manufactured in 1967/68! 

Updated: Google says they were availabe in the 40's!

Title: Re: Low Fuel Sending Unit
Post by: jwc66k on August 26, 2012, 11:38:49 PM

Diodes date from about 1890-1900 although they're not the same as what is used today. The "sensor", aka thermistor, used in the low fuel circuit provides a direct electrical path when not immersed in a liquid thereby providing an electrical path to actuate the relay to provide voltage to the warning light. That means it shorts when there's no gas (or the other way around).
Jim