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Gauges reading wrong

bigdaddyinacaddy

bigdaddyinacaddy

Obsessed
Messages
120
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Location
Jena, LA
Hey guys

My fuel gauge isn't reading right. When I fill it up it goes wayyyy down past the "F" almost touching the needle of my oil pressure gauge. My "E" is right between the 1/2 and 3/4 mark, had to figure that one out the hard way.

When my key is off, my oil pressure gauge is way past zero, like 9 o'clock, and stays like that until I crank it. Which leads me to believe my reading is wrong, and would be great because its been kinda low. I have a new OPS in the box and planned on replacing it while I've got my intake manifold off later this week and doing a relay mod.

My main question is, where do I start?

Thanks
 
X2 start with grounds and add a ground strap from the frame to the engine and from the body to the engine. I had a gauge go nuts with a failed body to engine ground. The small wire from the battery to the body isn't big enough.
 
Hook up a temporary manual oil pressure gauge to know when your electric is correct. You could have (like previously mentioned) bad ground causing all gauges to be off, or individual problems. The fuel level sending unit in these trucks are frequently off but that is WAY off.
 
Are you doing something other than ops removal that requires intake removal? I've always removed the ops with a plumbers basin wrench. Lowes even sells one for a wratchet, but a cheapie does it in 5 minutes.
 
hookedup50 said:
Are you doing something other than ops removal that requires intake removal? I've always removed the ops with a plumbers basin wrench. Lowes even sells one for a wratchet, but a cheapie does it in 5 minutes.
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95 OPS port is back behind DS head. PITA to get to IMO. Don't need to pull manifold, but he is swaping to an "f" lower intake (non EGR). The basin wrench works good on 96 & ^.
 
Ok I'm gonna check all my grounds when I've got my truck apart. Planned on taking my inner fender and manifold off, cause my turbo is stuck on and I don't feel like messing with it while its on the truck.

Is there an instrument cluster ground? Can anyone point me in the direction of which grounds may be the ones that work these gauges? I thought about the fuel sender too, but since it is such a constant wrong reading I think it is something in the grounds.

Where is the ops? I thought it was in the valley
 
Fuel sensor grounds on top of the frame by the fuel tank. Gauges ground to the body best I recall. Again put a big ground wire from the body to the engine.

Grounds by the trans dipstick on the engine are critical.

Fuel level sensors going "open" will read over full some years and under empty other years.

Possible both sensors have failed. Burning oil sells a bulletproof fuel level sensor.
 
Ops is behind drivers side head just above bell housing (post 7) on your truck, which is far more prone to leaks because it is hard to reach.
 
Burning oil said:
You should have your ATT today!!
Click to expand...

yessir i'm about to go pick it up right now. About 10 miles to my post office, i live in the middle of NOWHERE

As for everyone else, thanks for the suggestions i will definitely be checkin grounds. I need functional gauges ya know? lol I will keep yall posted.
 
So i'm actually just getting around to checking out my fuel gauge. After about an hour crawling around under my truck with a maglite, I can't find the fsu ground. I found the static ground on the filler but other than that it doesn't look like i have any stray wires going to or from my frame. Can anyone give me a more precise location? When I unplug the connector for the fsu, the gauge reads over full, about 4-5 oclock. Plugged in it reads inbetween half-3/4, I have about 5gal in her right now.
 
Thats the only ground. No additional for FSU. FSU does'int need a ground. Sounds like yours is FUBAR? If you have a FLAPS then plug in a new FSU into truck and while holding it in your hands move the float up and down to see what the gauge does (Might need a friend to view the gauge?).
 
The ground for the fuel tank sensor is by the fill neck hose on top of the frame best I recall. It could also be toward the back and be shared with the tail/brake lights. Just follow that wire bundle for a single black wire coming off it near the fuel tank going to the frame.

Again a big three kit for grounds may help...
 
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