Jump to content
Sign in to follow this  

Fuel Gauge is bust

Recommended Posts

i have an 88 f-150 with the dual tanks, both gauges are bust, they show over 'F' until i get down to around 8 gallons, then they flop til 2/3 gallons and then it shows 'E' any idea what it could be?

so far ive checked the ground on the tanks, but thats it. Ive heard some people say that its the sending unit, but i dont want to shell out $80 if its the wrong part.

The tanks are 16 gallons.

Thanks!

Share this post


Link to post
Share on other sites

hAVE YOU TAKEN THE DASH APART LATELY? OR INSTALLED any new electronics?

My #1 guess would be that there is a relay that has gone bad. It has one gauge and 2 tanks correct?

Share this post


Link to post
Share on other sites

Without diagnosing this myself, let me ask a few questions....did both tanks start doing this at the same time, or was it first one, then the other?

Most cases I come across where this is going on, it's the sending units are junk. Like 9 out of 10.

Disconnect the fuel sending unit at the sender (this sucks, you're gonna get dirty and scraped up), then use an ohm meter across the sending unit wires.

On Ford the sending unit should read between 8 and 12 ohms when the float is at the full position, and 60 to 86 ohms when it's at the empty position. No change, "skips" in the reading or readings that are out of range would all tell you a new sending unit is needed.

Share this post


Link to post
Share on other sites
i have an 88 f-150 with the dual tanks, both gauges are bust, they show over 'F' until i get down to around 8 gallons, then they flop til 2/3 gallons and then it shows 'E' any idea what it could be?

so far ive checked the ground on the tanks, but thats it. Ive heard some people say that its the sending unit, but i dont want to shell out $80 if its the wrong part.

The tanks are 16 gallons.

Thanks!

Unplug the wire to the sensors, does it fall to empty? If so, its the sender itself.

Usually they will develop an open and default to empty, reading full is kind of different. If you have a poor ground at the instrument voltage regulator (it regulates gauge volts from 5-8 volts (Toyotas use 5 volts, some domestics where 8 volts) and if it has a poor ground at the regulator, then all gauges that use the voltage will read higher. This includes coolent temp etc. The regulator is usually part of the cluster or part of one of the gauges itself. Soing to be a small black transistor looking unit, 3 wires.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×