Fuel gauge problem.

[Ogonz9494]

For a while now the fuel gauge on my 92 i4 ranger stopped reading correctly. Now when truck is on it usually reads over full and goes back down while driving and then back up. The truck has a brand new fuel pump and had this problem before I installed it, I thought it would fix the issues as well but it didn't.
Has anyone had this problem and a fix for it?

 

[RonD]

Google: ford ranger anti-slosh module

That is one common problem, this module prevents gauge from swinging up and down every time you go around a corner and gas sloshes from side to side in the tank

1989, and up, Ford fuel gauges and senders(float in the tank) use:
10 ohms Empty
158 ohms Full

Behind the dash is a 5volt pulsing power supply that powers the fuel gauge, if gauge works at all then this is OK.
The anti-slosh module is also on back side of dash.
Then there is a Yellow/white stripe wire that runs from the dash to the sender in the fuel tank.

So 158 ohm is high resistance, or NO connection, so if yellow wire had intermittent connection then gauge would go to Full when yellow wire lost connection then read correct level when it had a connection.

A short to ground is 0 ohms, no resistance, so a short on yellow wire would show Empty

So my guess would be yellow wire has a loose connection somewhere or Slosh module does.

The sender also needs a good ground, a loose ground could show same symptom, sender can be grounded at frame near the tank, same ground point as Fuel pump ground, or it can be grounded in the cab, passenger side foot well usually.

 

[Ogonz9494]

Hey Ron thanks for the info man! Seems like you know your stuff, I'm going check that out this weekend and get back with you. Thanks a ton!

 

[Jaelaw89]

Google: ford ranger anti-slosh module

That is one common problem, this module prevents gauge from swinging up and down every time you go around a corner and gas sloshes from side to side in the tank

1989, and up, Ford fuel gauges and senders(float in the tank) use:
10 ohms Empty
158 ohms Full

Behind the dash is a 5volt pulsing power supply that powers the fuel gauge, if gauge works at all then this is OK.
The anti-slosh module is also on back side of dash.
Then there is a Yellow/white stripe wire that runs from the dash to the sender in the fuel tank.

So 158 ohm is high resistance, or NO connection, so if yellow wire had intermittent connection then gauge would go to Full when yellow wire lost connection then read correct level when it had a connection.

A short to ground is 0 ohms, no resistance, so a short on yellow wire would show Empty

So my guess would be yellow wire has a loose connection somewhere or Slosh module does.

The sender also needs a good ground, a loose ground could show same symptom, sender can be grounded at frame near the tank, same ground point as Fuel pump ground, or it can be grounded in the cab, passenger side foot well usually.

I’m sure this is a dead post but I’m having a similar issue.l, and I had a question. The ground for that wire harness you’re saying is in the cab or on the passenger side. Which wire do I test to see if it’s grounded? Also do you have any idea why I wouldn’t be able to get my gauge cluster out. There doesn’t seem to be any give in the Speedo cable. Thank you

 

[RobbieD]

. . . why I wouldn’t be able to get my gauge cluster out. There doesn’t seem to be any give in the Speedo cable.

The cable is held by a retaining clip underneath, below the driver's seat. Crawl underneath, pry the cable out of the clip and push it through the firewall grommet, with the cluster mounting screws removed. This will push the cluster out of the dash a little, and give you room to reach behind to undo the two electrical connectors, and then the speedo cable itself.

Squeeze the smaller ends of the connectors to release them, and then feel for the high flat spot on the speedo cable end; push down on it and the cable will release.

Once you do it, it'll be easy from then on.

Good luck!

 

[Brain75]

not that your issue is the same as the original poster, but "over full" or well past empty is very indicative of a short or open in the ground (the needle only goes past full or past empty when there is no resistance or infinite resistance).

 

[Jaelaw89]

not that your issue is the same as the original poster, but "over full" or well past empty is very indicative of a short or open in the ground (the needle only goes past full or past empty when there is no resistance or infinite resistance).

So mine reads erratically. It’s will occasionally move to full then crawls itself back down to sit empty.

 

[lil_Blue_Ford]

So mine reads erratically. It’s will occasionally move to full then crawls itself back down to sit empty.

Sounds like a problem with the anti-slosh system. Unfortunately I don’t remember the details…

 

[Jaelaw89]

Sounds like a problem with the anti-slosh system. Unfortunately I don’t remember the details…

I’ll see if I can find more information about that. I was just going to try to test the gauge itself.

 

[flyin-lowe]

I have been fighting a similar issue. I put in a new fuel pump with sending unit from Oreilly in a couple weeks ago. At first, it went over 250 or so before it dropped below full. Then as it got close to 3/4 full I was due to put gas in it. I put 5 gallons in and it went the wrong direction, from 3/4 to half full. I drove it about 40 miles that night and during that time it went all the way to empty with the fuel light on and then minutes later it would go back to full. Pulled everything back apart and found the wiper/float laying in the bottom of the tank. I already had a new Bosch fuel pump on hand as I read some bad reviews on the Orielly branded pump. They gave me a refund and I put the Bosch unit in, seems to be fixed. Good news is the Bosch unit from Partsgeek was over 100.00 cheaper than the Oreilly unit. Fingers crossed as this is the only issue we have had with this truck in the few months we have owned it. I have been fighting it for a month or so...