Sending unit help

[michael.bohn]

I've had this replaced 2x but still no go. The shop is telling me the unit doesn't ohm out consistently. This most recent one was from BJs. Is there a common issue with replacements? Does my tech not understand something about these units on a jeep?


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[Tatsadasayago]

If you have a 79 or earlier FSJ, you may be using the wrong sender. From 72-3 until 79 the senders used a 10-70 Ohm variable resistor, which was the opposite of the common GM units of the period.
Help your FSJ brethren out by sharing the year and model of your Jeep so we can help you.

[memo43]

I has the same issue,
My sending unit and gauges where all after market, after messing up the sending unit arm, a quick to the parts store I was in the same boat, not reading correct. A quick call to the tech section in was told that I had to use there sending units since they are calibrated to there stuff. Though it was a sales gimmick, another trip to the parts store to ems up with the same issue.
I got one from the gauge manufacture an everything works as it should.
Also is your sending unit grounded properly?

[tgreese]

What's wrong with your old original sending unit? I had this problem on my CJ-6, and eventually put the old sender together with the new float, gasket, and lock ring. The sender should have a specific resistance at each level (empty, half, and full) and sometimes it would read, sometimes not. Mainly it would go open intermittently.

Having to relay this info second-hand to BJ's is not ideal... it would be better if you could test the unit yourself. Do you have a multimeter? Check that the sender gives you the correct ohms reading (resistance) at each position. As electrical measurement's go, this is one of the easiest ones.

As mentioned, you should put the year, model and equipement of your Jeep in every post. Most of us put this info in the signature file, so it's included with every post.

The TSM for your year will tell you what resistances the sender should be ... but I expect this is a problem with the electrical or structural integrity of the sender, not a "wrong part" issue.

[michael.bohn]

Apologies, '79 J10 Golden Eagle


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[michael.bohn]

Thanks all,
The original issue was zero reading on the stock gauge and it diagnosed as being the SU, seemingly was all original but who knows. I'll get on the horn with BJs and my multimeter when they're back in a day or two.
I'll make a point include year, etc when posting!


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[letank]

sending unit of what? gas, coolant, oil?
the coolant has the CVR, so if the coolant is skewed all the other values will be off... time for the CVR mods

http://www.fsjnetwork.com/forum/viewtop ... 4&start=20