like i said what are the ohm levels full and empty for a 91 yj. i have to know them to order my autometer fuel level guage

I got this from the article on how to swap a CJ dash into a YJ. http://www.off-road.com/jeep/swb/articles/dash.htm

0 ohms =full, 44=1/2 and 88 = empty

All I know is.......When the guage says 1/2 full or 180 miles on the OD.......I need gas. Fawkin thing........$170 bucks for a new sending unit? Did they KNOW these things would go out? :mad:

Mine is even more screwd up because I did the 15 to 20 gallon tank conversion that late model YJs can do. I got about 100 miles before it gets below full.... and then 100 more miles its on empty. I think there's a recall for some fuel sending units on YJs, but not sure.

Dont have an answer for your question but am kinda hopeing yj's use the same one as Tj's. Since installing a SBC into my TJ i have been living without a gas guage. I do have an auto meter installed but it was out of my drag car and was supposed to be used with a ford sending unit. It doesnt give any reading at all on mine except when it's REALLY FULL it gives about 1/4 tank for about 5 miles then goes to empty and stays there. I tried to measure the ohms at the sending unit but my ohm meter is screwed up and doesnt work so....
Thanks for any info,
Dave

ok in that article he states "YJ has a 0 ohms =full, 44=1/2 and 88 = empty. Seems the CJ is about opposite, with 73=empty, 9 = full. " that is not oppisite that is about the same so theres a typo there. i found this statement in another article by a diff person " I found out later that the factory ohm readings for my 1991 YJ (2.5l) are 1 ohm empty and 88 ohms full. I have since replaced the Fuel Gauge with one that has ohms of 0 ohms empty and 90 ohms full. " the article here is at http://www.off-road.com/jeep/reviews/dash/rlwdash.html

so basiically i have 2 answers of which i dont know which is right. im guessing 0 empty and 90 full is right any body that can verify this?

Originally posted by yjtj
so basiically i have 2 answers of which i dont know which is right. im guessing 0 empty and 90 full is right any body that can verify this?

Ya know, I'm in the market for gauges right now too and I've looked far and wide for ANY aftermarket gauges that give a FULL reading at 0 ohms, and there just aren't any... I'm thinking ether the first guy is messed up or the YJ just has a very unique fuel sender...

Sorry that doesn't answer your question (or mine).

Tell you what: I'll send some e-mails to VDO, Autometer and whomever else I can think of and see if any of them know... You do the same and if either of us learns anything, we'll post it here. Deal?

Jake

After a little more research with Google, I'm thinking the first guy was right and the YJ gauge really is "backward":


http://www.bc4x4.com/faqs/yj.cfm?cat=10&faqid=102

Maybe I'll just say fawk it and get a new sender. I gotta drop my tank to plumb the new fuel pump anyhow...

Jake

Call up the sponsor of this page they can tell you for sure...this was just alked about not too long ago:rolleyes:

heres the thread(no info other than to call steve n)

http://www.pirate4x4.com/forum/showthread.php?s=&threadid=34092&highlight=ohm

so would this be the same for a 83 CJ-7 because i have a autometer fuel guage for a chevy and it does not work at all. i got the ohm numbers from myh dealer once but i lost that info. any idea what the ohms are for a stock CJ-7 Sending unit??

i know the chevy guage ohms are 0 empty and 90 full so you prolly need the one thats 73 empty and 8 to 12 full.

well i figured it out. i dug out my 91 service manual (i was to lazy to do this before hoping for a quick answer). it says: empty = 0, 1/2 = 44, full = 89

this means the cj is opposite at 73 empty and 8 to 12 full since the chevy unit didnt work on his cj

CJ sender resistance specs are ...
* 73 ohms Empty
* 23 ohms at 1/2 tank
* 10 ohms Full

This and almost any other info you need for a CJ is in my article on this page ...
CJ Gauge & Sender Diagnostics (http://www.monsterslayer.com/jeep/Gauges.htm)
Copys are also posted on the Off-Road and 4X4Wire web sites.

A while back, a guy asked me to help figger out how to convert a YJ tank's sender to work with his CJ gauges.
Since the resistance values ARE backwards (but simular high and lows) between the two I suggested he reverse the wires on the YJ's sender's resistance wiper .... WALAH! ... it worked.
Not perfectly but reasonably well ;) .

I ran into this same problem replacing gauges on a cj. You can buy a variable potentiometer from radio shack for about 2 bucks. Hook it up with a jumper wire in-line with an ohm meter and read the resistance while turning in or out the small screw on the potentiometer. This will also tell you if your gauge is toast. On a side note, the autometer gauge I used for fuel bounces all over the place due to a lack of heavy grease controlling the needle...as found on stock gauges. Had I known this I would probably have taken the gauge apart and applied some dielectric grease to control the movement. Don't think that will work for the air core gauges though.

funny how there is a TSB for these damn senders and gauges and no recalls have been made...I guess its not safety or emission control related, so running out of gas and burning up a fuel pump and choking the engine can't hurt :mad: