Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[grc]

Sending unit connector

[grc]

Trim Pot

[grc]

Trim Pot Location

[Twolanerider]

The trick was finding one with wire leads, since most are made to be soldered to a circuit board. I'll post details and photos tonight from my home computer.  

A good source for a part made specifically for this purpose would be a company called Corvette Central.  Old 1st and 2nd generation Corvettes have a similar problem because the new sending units provided for the engine temperature gauges don't work over exactly the same range as the original ones did.  So, consequently, the gauges aren't accurate.   Come to think of it the same problem exists on early Thunderbirds as well so CASCO or Thunderbird Center or other of the specialty shops for the bird restorers should have a similar part also.


For a particular part that is setup to function as a variable resistor with the leads already on it to work from see part number 301290 at Corvette Central at:


www.corvettecentral.com

[ggraves427]

You guys have a wealth of knowledge.  I appreciate the info.  

[grc]

 If I run into any trouble would it be OK if I came to your house and  let you do the whole thing while I drink beer out of your refrig.  [smiley=drink.gif]  

No problem - I actually enjoy doing this stuff.  Awfully long ride from Texas to Indiana for a free refreshment, however.  [smiley=laugh.gif]

Jerry

[ggraves427]

OK.  I finally got the resistor installed as directed.  As mentioned earlier I have found out the hard way that I'm completely out of gas at 170 miles.  I have 167 miles on my first tank of gas after making the moification and the the needle is right on empty where it should be. My low fuel light came "on" at about 140 miles.  Yes the needle is a little left of "F" when I fill it up, but I don't worry much about having a full tank, it is running out of gas I worry about.  I have been using my odometer for a gas gauge for so long it feels good to have a working gas gauge.  Thanks for a really great idea!  

[Rsantucc]

Thank you for posting this. I am trying to follow your directions but am unable to get the pictures. Could you repost the pictures or better yet send me these directions with the pictirs to my personal email address of Rsantucc@nycap.rr.com. Your help and quick rpely is apprecaited.

Regards

Robert

OK - the parts I used are as follows:  1- 50 ohm trim pot, p/n RWV-42-9-112500 from Surplus Sales of Nebraska http://www.surplussales.com/Potentiometers/Pots-15.html  
1- male terminal p/n 73190-96 & 1- female terminal p/n 73191-96, both from H-D.  The terminals are not necessary if you want to cut and splice, I used the terminals to make it easier to go back to stock if it didn't work the way I thought it would.

Remove the seat and locate the 3 wire connector just aft of the fuel tank (see photo).  The wire you want is the center wire in the connector, yellow with a white stripe.  Pick a convenient place along this yellow/white wire to cut the wire.  The potentiometer has 3 wires, red, yellow, and green.  You will need to connect the red wire and green wire to one end of the sending unit wire, and the yellow pot wire to the other end of the sending unit wire to complete the circuit.  I prefer solder and shrink tubing for this type of splice rather than crimp connectors.  Once the splices are completed and insulated, find a protected location for the pot and either secure it with tie straps or double sided mounting tape (see photo's for my choice of location).  Tape or strap the wires to prevent damage.

To make the initial adjustment, I had the tank full and turned the pot screw until the gauge needle was just touching the left side of the "F" (normal was hard against the peg past the full position).  This gave me the result I wanted, which was to have the gauge read 1/4 with slightly more than a gallon remaining.  Each individual will probably have a different preference, and the nice thing about this method is that it only takes a few turns of the screw to customize the gauge reading.  Be aware that if you add more resistance to give a bigger "reserve" cushion, your gauge will not read full when full.

You can also just splice in a regular resistor (non-adjustable) to lower your gauge reading if you know how many ohms you wish to add.  I measured my resistance after adjusting the pot and found that I had added 7 ohms to the circuit to get the results I wanted.