Electrical Problems

[JeepFreak21]

I hate electrical problems! My oil pressure guage seems to have a bad ground.... does anybody know where the first place to look is? I already tried the obvious - the sending unit.
Thanks,
Billy

[5-90]

Have you checked the engine ground straps? The first sign of losing block grounds is erratic gages... Replace those open Aluminum braided things with some REAL wire!

Even if it doesn't work to fix your gage, it probably needs to be done anyhow...

5-90

[Eagle]

The sending unit IS the ground. That's why there's only one wire to it. You can esily check the connection between the gauge and the sender. Remove the wire from the sender. On the older XJs, the gauge should peg all the way to the right. I believe post-91 it will zero.

Now short the wire directly to the block. Whichever way the gauge moved with an open circuit, when you ground the wire the needle should move to the opposite extreme.

If it does that, your problem is the sending unit.

[5-90]

I'd read his post as saying he'd already checked the sender - of course, if it's been replaced recently, most sealers can cause a shonky ground for self-grounding sensors as well. Still, if the engine block ground is going awry, the oil pressure sensor is about the farthest from the ground points and gets oil on it, and has always seemed to be one of the first sensors to go stupid from a bad engine ground...

Stop me if I misread anything, tho...

5-90

[Eagle]

Originally posted by 5-90
I'd read his post as saying he'd already checked the sender ... Stop me if I misread anything, tho...

5-90

He did say he tried the sender, but then he asked about the ground. The only "ground" for the oil pressure gauge (or the fuel gauge, for that matter) is through the sender.

If the oil gauge uses the same circuitry as the fuel gauge, you can also test it using resistors in place of the sender to see where it reads. For an '88, the range is 0 thru 88 ohms. Zero should read zero on the gauge, and an 88 ohm resistor should put the gauge at the 80 psi mark.

I'm not entirely sure I believe this, but according to the 1994 FSM the Chryco gauges work in reverse from the older AMC gauges. The reistance range is 5 thru 105 ohms, but 5 ohms (according to the manual) is the 80 psi end of the scale, and 105 ohms is zero on the gauge.

[CheapXJ]

umm... unless they changed it on post 90 XJs... I thought the strap was the body ground, and the engine was the first thing to get grounded?

[JeepFreak21]

I only checked the sending unit to see if there was a loose wire. I will pull the sending unit and clean it off and stick it back in. I don't think it's the engine ground cuz that's the only guage that's messin' up. The needle pegs all the way to the right by the way and it's a 95 cherokee. Thanks for the help, I'll see what I can come up with now.

[csudman]

Hijacking my first Thread, Kinda. I've got a 92' that the temp gauge goes nuts on every once and a while. I put a 180 thermosate on it a year a go and its never registered over 220 since then, I always wondered if was realy keeping it that cold or the gauge wouldn't let it read any higher. Any way, everyonce and a while on hot days while climbing hills or in general really "running" the engine it'll reach 220 and then drop to 0. I'll let off the gas for a sec and she'll climb back up. I'm worried I might be really screwing somthing up. To lazy to change the termostat back to 200 or 220 cause its never overheated. Thoughts?

[Lou]

csudman,

I think you need to reconsider what you put in your sig line.

[5-90]

Oh - I still haven't dug up all my manuals just yet, and my working knowledge on checking everything is Renix...

5-90

[Matthew Currie]

Originally posted by Eagle


I'm not entirely sure I believe this, but according to the 1994 FSM the Chryco gauges work in reverse from the older AMC gauges. The reistance range is 5 thru 105 ohms, but 5 ohms (according to the manual) is the 80 psi end of the scale, and 105 ohms is zero on the gauge.

With the Chrysler oil pressure gauge, unplugged = high, and grounded = 0. If you use an idiot light sender with gauges, max = "light off," 0 = "light on."

With the temp gauge, unplugged = 0, and grounded = max, so if you use an idiot light sender, it reads nothing until it overheats, then reads max.

[csudman]

I really did hit a girl on a bike. Not trying to be racial or anything sorry of it offended you.

[rixXJphx]

Originally posted by csudman
I really did hit a girl on a bike. Not trying to be racial or anything sorry of it offended you.
Doesn't seem to me like it would matter what her race/color is.
If you had hit a deer, it wouldn't matter whether it was a mule or white-tail (nor buck/doe, for that matter).

Frankly, it reads like something a bragging klansman would post.

[frsno jeeper]

Originally posted by csudman
I really did hit a girl on a bike. Not trying to be racial or anything sorry of it offended you.

i thought it was funny. :dunno:
im no klansman by the way.

[Lou]

Csudman,

Thanks for the response. No, it goes beyond race.

I don't know if you have any kids, but once I became a parent, I became ultra-protective of you my own kids, and others kids.

Also, it did not help that I had just finished reading a thread on JU by someone who had T-bone a car. Goes into graphic detail about the injured kids, but his only concern seems to be for the XJ.

Your sig seemed insensitive to the pain that she and her parents would have felt.

Thanks for listening,

Lou