CRAP Fuel sender unit!

[ndnatty]

I have a 79 cj7 and I have to replace the crappy fuel sending unit all the *#@* time! What happens is the wire that is wound to provide resistance keeps breaking. So when the fuel level drops to the break in the wire the gauge drops to zero! What a pain!!! Does anyone know of an adaptation/upgrade/improvement to eleminate this aggravation??? Seems like there should be something to do. ANY help would be appreciated!

 

[odjeep]

A jeep with a fuel guage that works???? never heard of it. the fuel guage in my 87 is the tripometer. when i had my 79, i used the odometer and a small notepad. also helps to keep a small can of gas with ya just in case. it the best thing ive come upon without having replace the sending unit every month.
od

 

[SenorCole86]

What is making it break? I can't imagine anything in there hitting it, so it must be an electrical problem. Check the wiring and whatnot. My '80 CJ7 is plagued by electrical problems due to an old and nasty wiring harness. So I'd imagine ages wiring is the problem. There my 2 cents, hope I helped. Good luck.

 

[Junkpile]

Light Problems

The first CJ that I ever owned (81 model) loved to leave me stranded on the side of the road. I gave up and started carrying an extra gallon behind the back seat. When I sold it, I told the guy that the gauge didn't work, and he said no problem. Cool. I talk to him a while later and the gauge was fixed. He said it was a wiring coming off of the sending unit that needed to be replaced. So I went home and took the fuel system apart on the new(er) CJ that I had. Couldn't find anything wrong, but it almost worked right all the way down to about 1/4 tank after I put it all back together. It's got to be wiring related. All my other CJs have had good gauges, so I haven't dealt with this problem in like 9 years.

Post what you find out about it, please. If you don't, mine will break next and then I'll be on here bugging you about it.

 

[ndnatty]

The fuel sender in my jeep is mechanical. A small gauge wire wrapped around a small cardboard piece. The float then moves a small metal piece against this cardboard piece making contact with the small gauge wire causing resistance. What seems to happen is the metal piece keeps breaking the small gauge wire, usually about half way. So when the float gets to this point, zero resistance and a fuel gauge that reads -0-. Have happened twice now! Has to be a way to upgrade this to get away from the design flaw.

 

[Robrt-Stephens]

The fuel sending unit is having troubles for two reasons.

First, the gauge wire ground is faulty and is a known problem with all the CJs.

CURE: Cut a hole in the floor of the bed over the spin out cap on the top of the gas tank, which is easier than dropping the tank, and pull out the sender, wire, and that phoney, engine stopping filter than gets the algea growing on it and stops our Jeeps in their tracks. Replace it all with a copper sender and solid wire dip to the float bottom. Screw in the cap and then make the cut out piece of the bed a cover with tapping scrrews so you can always get to the tank without dropping it.

Second, replace the gauge for $35 if it is old, and make sure it is wired for ground across to the temp gauge too--this is OEM. Mine works perfectly and always has since repairing it 14 years ago when I rebuilt VEX as a total.

I won't tolerate gauges not working and they should work perfectly and do, even my 4WD inidcator light and other APUs work perfectly as they should.

If you replace all wires as you go wth super heavy ones and grounds to match, your electrical problems disappear.

The rule is no electrical system is as good as the weakest ground, on 12 volt systems. So, beef it all up with the heaviest wire practically you can use.

I use 2/0 (not 2 gauge), welding cable with copper ends, to 2 - 1000 amp batteries in parallel (not isolated), powered by a 200 amp alternator. All my lighter wiring is 12 gauge, no smaller.

Strangley, lights, indicator lights, marker lights, etc, last about 10 times longer since there is no resistance to speak of in the system, under this arrangement.

I hate electrical problems!!!