Fuel tank sender repair.

[CandBMotorworks]

Not a bad idea

I tested it in my garage with a multi-tester to make sure that both the resistor and the low-fuel warning light circuits worked. But it couldn't hurt to do another test before I get gasoline all over it.

My main concern isn't whether it will work at all, but whether it will be reasonably accurate. We've all experienced cars that seem to burn through the second half of the tank MUCH fast than the first. Having a reliable and reasonably accurate gauge makes long distance travel much more appealing.

 

[budgetzagato]

What I'd do...

With a carbed car you have a slight advantage; you can install the sender, drive it until it's low, and carry a full gas can. Reset the odo when the light comes on and drive it until it runs out of gas. Use your gas can to get home, and ponder the range given by the warning light. If you want more range, bend the contacts for the light on the sender to provide the desired results. :bla:

It's a bad idea to do this with an injected car. :hmm2:

 

[CandBMotorworks]

It WORKS!!!

I followed Tony's suggestion and connected up some alligator clips to each of the positive leads and one to ground, put the key in and moved the float armature to test. As I moved the gauge did, too, and at low the low fuel light came one. Success. That's one more punch list item checked off.

After reinstalling it, I checked it again and it showed about 3/4 tank. I thought I had filled it up and then only drove about 30 mi, so I'm still not sure on the accuracy. Maybe the second half of the tank will last longer than the first (on the gauge).

I also checked my "fix" on the leaky impeller for the windshield washer tank. It seems to be holding water now, so I reinstalled it and checked again to ensure the impeller works. It did, so I consider that another success.

I continue to check off these little "punchlist" items as I bring it back to full functionality and operability. On my list still is to fix or replace the noisy radiator fan and to figure out why I have no illumination in the dash when I turn on the lights. I also need to lube the speedo cable (new) and/or the "guts" for the speedo so that it will quit chirping at me. And eliminate a noise coming from the front end that I'm hoping is just an alignment issue and not bad hub bearings. And so on.

 

[ianlawson]

Speedo inner cable 'chirp'.........!!

....I also need to lube the speedo cable (new) and/or the "guts" for the speedo so that it will quit chirping at me.......

.......if the inner cable is new, often the cause of that 'chirp' or scratchy noise can be that the inner cable is SLIGHTLY too long. The noise comes from the inner cable 'bunching up' in the speedo head.
A common fix is to remove the speedo cable inner, and CAREFULLY grind (on an electric grindstone) a small amount off the end that goes into the speedo head. Only about 1-1.5mm needs to be ground off, just enough that the cable inner is not 'compressed' into the speedo head entry when installed.
Re-lube the inner cable slightly, and thread it back into the cable outer. You may have to disconnect the cable from the trans end when doing this job.
Good luck!

cheers, Ian - NZ

 

[CandBMotorworks]

Update...

The noise from the front end WAS a bad bearing. Both front end wheel bearings have been replaced. Interestingly, the cage for the bearings is made of plastic. The bad one had a cracked cage and metal shavings in it.

I also got a replacement fan, cleaned it up, media blasted and repainted the shroud and put the whole thing back together. No more squeal from the radiator fan.

Both of these projects were done a couple weeks ago. I found out today that my buddy JB drove the car to an old part of town where there was an old home show going on. He parked the car in a prominent spot with a FS sign and a bunch of our cards. Hopefully, someone will fall in love with this one so that we can get some $$ to start working on the 74 x.


EDIT: I just realized that this was someone else's thread. Sorry TonyK! BTW, thanks for your photos and info. Both made the job pretty easy for me.

 

[dwoof]

For those that like the challenge it is possible to repair the fuel tank sender resistor by rewinding it.

From ebay I located 30' of 38 guage Nichrome wire. Resistance is 43 ohms per foot. You need about 10 feet. $5 for 30 feet of wire.

First step with the sender removed is to pry up on the tab that keeps the sender body connected to the mounting base.

Here is what you will need to do the repair. My tired eyes need a 5X magnifier that straps to my head to see this fine detail. Jacobs on Line supplied the wire for the repair.




The sender resistor slips out of the body and you can see the broken part.



Next I needed a crimp to make the connection to the body of the resistor. OEM uses a crimp, no solder is used to make the connection. Take a crimp and open it up like this.




The eye will be cut off but the open part of the crimp is used to go around the stake on the resistor body.

Start at the wire terminal connection of the resistor body and push the new wire through the rivit then wrap several turns around the stake connector. Use the expanded crimp to hold the new wire against the wire stake, crimp to make connection. Now with the body mounted in a small vise start winding. The edges of the resistor body have notches for the wire to be wound into and prevent it from slipping down the resistor body. The wire only .038" is very strong and can be pulled to keep tension on it.





When at the end several wraps that loop under are required to terminate the nichrome wire. The body of the sender will captivate the end of the wire when inserted. Slide back into the sender body.





Do a resistance check and low fuel light check. You should have about 400 ohm reading when the tank is low and about 8 ohms when the tankView attachment 35285View attachment 35286View attachment 35287View attachment 35288View attachment 35289 is full.


TonyK.

Grimsby Ontario Canada.

Just cleaned up my sender. It still worked fine, my range was 8 ohm to 335 ohm. Float had about a teaspoon of fuel in it.