fuel sending unit

[graycj7]

When I put the test light on the fuel sending unit the light does not flash. I have John Strenks basic troubleshooting for cj gauges. He states that if the light does not flash then there is a problem with the wiring harness. I don't know what I should be looking for to correct this problem. I have installed a new gauge and I know that it is working. Any help sure would be appreciated. Thanks Scott.

 

[gpdno]

I would look for a broken wire/connection. Also check for a bad ground.


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[graycj7]

With this 85 CJ7 when you turn off the ignition does the fuel gauge read whats in the tank or should it go back down to empty. I know that in my 68 Camaro it stays at the level that's in the tank. Could some one clear this up for me thanks.

 

[mtnwhlr]

It should go back down to empty.

 

[graycj7]

Mine is staying at about 1/4 in tank. Can you tell me why its not going back down to empty. I have run the ground from the sending unit directly to negative battery post.

 

[ThisGuyUKnow]

Probably a bad sending unit, or their is enough corrosion tha the float is sticking. What wire are you checking with the light? I think a multimeter would be a better diagnostic tool than a light.

 

[Torxhead]

If you have installed a new gauge correctly and it should be 2 new gauges, temp and fuel, some sending unit research should be done. Might be time to drop the tank, change fuel pick up filter , lines, clean the tank inside, along with checking ohm readout on the sending unit.

Edit: Oh yeah, yesterday I put mine back in for like the 3rd or 4th time. Its a lot easier when the gas is pumped out.

 

[ThisGuyUKnow]

If you have installed a new gauge correctly and it should be 2 new gauges, temp and fuel, some sending unit research should be done. Might be time to drop the tank, change fuel pick up filter , lines, clean the tank inside, along with checking ohm readout on the sending unit.

Edit: Oh yeah, yesterday I put mine back in for like the 3rd or 4th time. Its a lot easier when the gas is pumped out.

Its still a PITA without fuel. I hate dropping the tank.

 

[graycj7]

Thanks guys. I have already cut an access panel to work on the sending unit I will take it out and clean everything up. I do have a multi-meter I will check ohms after its cleaned. As I move the float up and down it should read on the gauge. When I installed it I installed a new temp gauge to. Today when I brought it up to temp it went all the way to hot. All wires and connections on this jeep have been cleaned or replaced. This is crazy.

 

[Torxhead]

When you remove the sending unit you can hook it back up, turn the key on and as you move the float up and down you should be able to see the gauge move. Too bad you can't get it to work right all I can suggest is checking the instructions and referring to John Strenk's pages. When you reinstall the sender, apply some o-ring lube or silicone to that rubber ring. There are replacement pick up filters, O-rings, and locking rings available.

 

[graycj7]

Thanks when I get a chance I will get back on it. I will post results. Today I installed a new temp sending unit in the cylinder head and the gauge still goes all the way to hot. At this point if things don't start to work right im going to buy auto-meter gauges. I think ill look at what they have right now.

 

[Torxhead]

When time comes for me to change temp and fuel gauges again, I would like to see if I could stuff those Autometers into the oem gauge locations. It would require some gauge rework though. I am on my 3rd set in 25 years using the oem style that was once made by Stewart-Warner of course.

 

[graycj7]

If I did go with auto meter gauges it would not bother me to mount them in the dash panel. Or mount them under the dash. Will see.

 

[canuckcj5]

I'm having a similar issue, my fuel gauge Dosent work, went to install a new gauge and it also didn't work, but I think I might have gotten the wrong ohm gauge, what's the ohm rating supposed to be? 73 ohms empty and 10ohms full? Or 0 ohms full?


And do I need to run something extra? I put a aftermarket temp gauge in on it's own circuit and was hoping to do the same since my speedo/temp/fuel gauge has never really worked properly

 

[Torxhead]

That is 10 ohms full. I have read about guys having issues with installing new gauges where they give up on the oem replacements and install Autometers or something like that. Other than following John Strenk's gauge page and the instructions that came with the oem replacement set, that is about all you can do:
Basic Troubleshooting for CJ gauges

 

[DHugg]

That is 10 ohms full. I have read about guys having issues with installing new gauges where they give up on the oem replacements and install Autometers or something like that. Other than following John Strenk's gauge page and the instructions that came with the oem replacement set, that is about all you can do:
Basic Troubleshooting for CJ gauges

There is another way, if you're an absolute glutton for punishment. Here's the link in the BUILDS section of this forum:

But you have to be desperate, as I was.

 

[Kafka]

I gave up on the OEM gauges. I got tired of running out of gas!

When I did my most recent rebuild, I bought a blank dash, and put in Stewart Warner Wings gauges, with direct sensors from the engine so I am getting accurate temp and oil pressure readings for once.

For what it is worth, Summit Racing has a great selection of gauges, some which look identical to the WWII and post war jeep gauges.

The problem is the Fuel gauge, which has a different Ohms (90-0) than the OEM jeep sender. So now I need to get a Stewart Warner sending unit. For now, the fuel gauge reads 1/2 full when the tank is full, and Full when the tank is empty! Still scratching my head over that one. (andd yes, I have checked and rechecked the wiring multiple times!)

Anyone have experience in swapping out the OEM fuel sender for a Stewart Warner fuel sending unit?

thanks,
jim

 

[graycj7]

If I buy a new fuel sending unit can anyone tell me which company they bought theirs from. I'm looking for a reliable source to purchase from. I want to buy one that I know will work. Thank you.