Gas Gauge Pegged >

[MrFreeze5]

Hey everyone! Ive been lurking around here for a little over a week now. Last week, I bought a 88 MJ Pioneer 2wd, 4.0/BA10 for $600. Its a little ugly, but it runs pretty well. I'm a little new to this Renix thing, although the rest of the Jeep I know well. Ive got big plans for this thing, and have a few other Jeeps to pull parts from for this build, but Ive got to get a few simple things fixed first.

 

When I got my MJ, most of the interior was already pulled apart, and the gauges were in bad shape. The gauge package it had was coolant, oil, volts, speedo, and a big gas gauge, but the gas gauge had no needle. I went to the junkyard and found a few older MJs and didnt really pay attention and pulled a cluster of a V6. Needless to say that didnt work, so today I went back and exchanged it for an XJ cluster. I already had most of the gauges, so I didnt need to swap senders or anything. The XJ cluster is from another 88 4.0, but none of my idiot lights work now(the XJ was auto). Not a big deal since the shift light irritated me and I know the emissions need matinenence. But thats not my real problem, Ill mess with them later.

 

The gas gauge will go all the way to the right, well past F, so its pointing straight right. It did the same thing on the 2.8 cluster too. I am guessing it is an issue with the sender, but I'm not sure yet since I havent checked that. I currently know of 3 comanches in the junkyards right now, but theyre 2 4 cyls and a V6. And I don't know how much gas I have left...:D I'm guessing it might be grounded out since it immediately pegs to the farthest extreme, well past the markings. But I am hoping for some ideas before I crawl up under it to check. I'm not sure if this is true, but from what I can tell the senders for the 4.0 arent available anymore, is that right? Thanks for the help!

[Harper]

It's not grounded necessarily. An open circuit will peg the fuel gauge on full with the key on. Check reading between the two wires at the sender disconnect. Should read between 0 and 88 ohms (0 for Empty, 88 for full). If it's higher then 88 ohms, the sender's bad. If it reads good, then the problem is in the wiring to the gauge. or the gauge itself. You can check at the instrument cluster wiring plug, terminal 17 to ground for 0 to 88 ohms to test wire. If it's good there, guess you've got a bad gauge.

[MrFreeze5]

It's not grounded necessarily. An open circuit will peg the fuel gauge on full with the key on. Check reading between the two wires at the sender disconnect. Should read between 0 and 88 ohms (0 for Empty, 88 for full). If it's higher then 88 ohms, the sender's bad. If it reads good, then the problem is in the wiring to the gauge. or the gauge itself. You can check at the instrument cluster wiring plug, terminal 17 to ground for 0 to 88 ohms to test wire. If it's good there, guess you've got a bad gauge.

 

Cool, thanks for the input, Ill check that first thing tmrw. I'm pretty sure it isnt the gauge itself because it did the exact same thing on 2 clusters. But so far I think thats the only thing I have ruled out :D.

 

An open circuit was my other thought. I wasnt sure which polarity it was, so that helps a lot. Thanks!!

[rcturgeon]

haha sometimes when I'm driving my gas gage will go all the way right way past full and then all the way left and back again and all over... then it stops and its done having a hissy fit.. but i think the sender is bad becasue no matter how little gas is in the tank i don't go below a quarter :D i guess i never run out of gas

[Jeepncreepn]

It's not grounded necessarily. An open circuit will peg the fuel gauge on full with the key on. Check reading between the two wires at the sender disconnect. Should read between 0 and 88 ohms (0 for Empty, 88 for full). If it's higher then 88 ohms, the sender's bad. If it reads good, then the problem is in the wiring to the gauge. or the gauge itself. You can check at the instrument cluster wiring plug, terminal 17 to ground for 0 to 88 ohms to test wire. If it's good there, guess you've got a bad gauge.

 

 

i have the same problem way past full... watching this for more info :hijack:

[MrFreeze5]

For the first few months I owned my MJ the gauge was just pinned to the right. Well, about a week ago, I noticed after I had been parked on an incline for a few hours and had to deal with a funny driveway that the needle was going crazy and the fuel light was on. The needle wobbles around like a drunken sailor after last call, almost like the sender is sloshing around, and whenever I stop, it will settle down to empty. It has been doing this for about a week now, the needle goes crazy when I'm moving, drops to E when I'm not, the light on the whole time. Weird.

 

Luckily, my fuel pump starts howling about 10mi before I run out of gas, so as long as I pay attention, I'm usually good without gauge :D

[88MJXLS]

Mine stays between just over half a tank of gas and just past full until it's about out of gas, then it hovers above E

Oh, and if I press the brake pedal at all without the engine running I suddenly have a 1 1/2 tanks of gas :rotf:

[ratrapp]

my gauge reads full when i fill it up but it doesn;t move until it's down to about half a tank then it starts working.it reads full and empty right but anything inbetween is sketchy.i figure as long as empty and full are right i can live with it especially since they don't make new gauge floats assemblys.