What Is the Value of this Resistor?
 

This carbon fiber resistor goes in a a 1950's Ford 6 volt gas tank sending unit.

Can anyone tell me it ohms value based on the color code and explain how you figured it out?

Thank you.

Re: What Is the Value of this Resistor?
 

If they use the normal colourcoding for resistors white is 9 and green is 5.
What is the issue ?
Carboncomp resistors drift in value from age...

Re: What Is the Value of this Resistor?
 

Based on available info and what the actual color of the tip is, this is a possibility. (green is the multiplier)

Re: What Is the Value of this Resistor?
 

The reason I asked is that I have an old Ford King-Sealy gas tank sending unit with s broken OEM resistor. I would like to replace the broken resistor with a new style carbon fiber resistor that are being made today. The broken resistor looks like the one shown.
Therefore, i need to know its resistance value.
QUESTIONS:
1. What does the gold band on each end represent?
2,.How do you know if the value is 95 or 59? Which end do you read from?

51 Merc: Thanks but your resistor reply confuses me. I was never good at electronics.

Re: What Is the Value of this Resistor?
 

This is a pretty decent chart for values by color code. https://www.electronics-tutorials.ws...tor/res_2.html


The carbon types were the common low cost resistor back before solid state circuitry became more common. The type could be off of its design resistance by 15% or more but it would likely still do the intended job.


A lot of newer stuff is metal film or combinations of different materials. The orange, gold, or copper color may or may not be part of the valuation. I don't see brown but colors fade. The width on the edges of the two color bands is wide where there appears to be no color paint but just the black color of carbon and the color bands are usually very uniform in width. The two ends are where it clamps in place so I don't know if those colors mean anything or not.

Re: What Is the Value of this Resistor?
 

Only you, who have it in your hand can determine the tip color.
Gold is not an option.
Either orange or brown (based on the image provided) looks like a possibility.
So until the actual color is determined you have two possibilities.

1.9 MgOh or 3.9 MgOh

Re: What Is the Value of this Resistor?
 

The gold or silver denotes the tolerance, in percentage. and is at the end of the color code,

Re: What Is the Value of this Resistor?
 

If the Gold ends is the tolerance, +/-5% and their are two other bands, White and Green, looks like it could be 95 ohms, 59 ohms or 900K ohms. Can you measure it at all to get a ball park?

Re: What Is the Value of this Resistor?
 

A person would need to measure the resistance of more than one of the type and compare that to the color bands. Tolerance was not a big thing on those types. The actual resistance would give a person an idea of which way the color bands go. Flip it over and it means something else. The bands are generally closer to one side than the other so that you can tell how to read the code.

Re: What Is the Value of this Resistor?
 

Not sure this helps much, but does show some different color code arrangements. It shows the Gold end bands, but only a single band in conjunction with the background color. Because the background appears to be Black, would guess it doesn't come into play. It would look like 900K.

Re: What Is the Value of this Resistor?
 

I need to open up some of the later ones & have another look. I think they quit using the carbon types later and just used a wire spool type so it could be adjusted. They must have had an assortment of those carbon types when they were testing out those units at King Seeley. I've seen different color codes on different units so they likely just installed ones that best met the accuracy specs they required on those units.


Some of the old resistors used dots of color along with bands. There wasn't a strict set of standards on anything but the actual colors. The way the colors were applied varied a lot between manufacturers.

Re: What Is the Value of this Resistor?
 

The last one I opened up was wire wound and adjustable like rotorwrench is referring to.

This one looks like it has the single center band.

The second photo is of a wire wound resistor. The measurements I got on this sending unit are 2-3 ohms on the heater wire winding and 8-9 ohms on the resistor. Based on this, the resistor may not have a multiplier. Violet would be 7 ohms if that is the correct way to read them, LOL.

Re: What Is the Value of this Resistor?
 

Trying to determine the value from old aged colors is a waste of time.
Measuring with an ohmmeter will give a fairly close value good enough for common use.

Re: What Is the Value of this Resistor?
 

Measuring would always be the best bet, but still interesting to ponder.

Re: What Is the Value of this Resistor?
 

From what "Pete" said, it has no value whatsoever.:rolleyes:

Re: What Is the Value of this Resistor?
 

If it is a high value carbon resistor then it may take an Ohms meter set for high resistance values. Resistors without wires can be difficult to get a reading on. The composition sometimes required more voltage be applied to get a reading. An old analog Ohms meter might be the best to use for checking one. Some digital meters get flaky at higher values.

The wire wound types would be easy to check.

When I worked on military helicopters, they used wire wound types to adjust the system resistance for the turbine exhaust gas temperature system (EGT for short). The best way to adjust them was with a resistance clock box. A person had to real careful to clean all off all the connections prior to adjustment. You can clip wire off of an adjustable spool but you can't add it back on. The systems had to be exactly 8 Ohms or 16 Ohms depending on the type of thermocouples used.

Re: What Is the Value of this Resistor?
 

The "gold" color on the ends may be conductive paint that forms the contacts of the composition resistor........Bob L