Broken Fuel Sender resistance wire, $3 fix walkthrough Options

[john77]

My sender stopped working and when I took it apart I found the resistance wire had snapped (this may or may not have been as a consequence of something stupid I did (IMG:style_emoticons/default/smile.gif) ).

I searched here first and couldn't find anything, so figured I'd post this fix in case anyone has the same problem in the future. As much as I'd like to take credit, it was largely informed by this post on The Samba

The wire in the sender is nichrome, a high-resistance wire. 12 inches of the broken wire from the sender read approx. 42-43ohm on my multimeter.

So, all you'll need is:
1. Soldering Iron
2. Solder
3. 42.2 ohm, 38 gauge nichrome wire for $3 from Jacobs Online


Step 1:
Use your soldering iron to heat and remove the solder attaching the ends of the snapped nichrome wire to the sender. Once you've removed the remaining pieces of wire, keep going until you've also removed all the old solder - underneath you'll find a hole in each of the tabs to thread the new wire through.




Step 2:
The nichrome wire comes on a cardboard spool. Remove enough of it to go from one tab down to the bottom of the sender and back up again + about 5 inches. Pull it through your fingers a couple of times to straighten out any kinks - it doesn't have to be perfectly flat.




Step 3:
Thread one end through the hole in one of the tabs you removed the old wire from. Pull an inch or so back on itself and then hold taut as you solder it in place.




Step 4:
Thread the wire through the metal contacts on the side of the float...




Step 5:
... and then down and around the black plastic piece at the bottom of the sender ensuring it doesn't touch the metal post (as in pic).




Step 6:
Now, going back up toward the top of the sender, thread it through the metal contacts on the other side of the float (so same as Step 4)...


Step 7:
... and through the hole in the opposite tab, again pulling back on itself to ensure it's taut, and then solder in place.


Once it's cooled you can cut off the extra pieces of nichrome wire either side of the solder on the tabs and reassemble the sender.

Then simply test your solders are good by either reconnecting it to the gauge and inverting the sender while still out of the tank to check the needle moves or, if you have a multimeter, connecting it to the two left pins (diagram below) on the top of the sender and watching the ohms increase/decrease as you slide the float up and down.




One final thing, when soldering be careful not to accidentally touch/burn the copper wire that runs the length of the sender and grounds the warning light... (IMG:style_emoticons/default/headbang.gif) If you do, a simple fix is to strip the insulation off a piece of electrical wire, remove the copper wire from inside and solder one strand of it in place of the broken copper wire.



John