masterf99

So I recently bought a 1989 Ford Bronco II, and it's in really good shape but the fuel gauge does not work. It sits at around a 1/4 tank, until I turn the ignition on, at which point it sinks to and remains at empty. I've checked all fuses associated with the gauge cluster, and inspected the wiring for and knicks or breaks, etc. I have purchased a new fuel pump, however, it did not come with the sending unit. The guy at the parts store assured me that it was built into the pump, but a search online show me a whole other piece, which has a float attached to it. I think that this Sending unit is the piece that I need to fix the problem, trouble is, it's seems to be very hard to find. Everywhere that I go and anyone that I ask, tell me that it's built into the pump, or that it comes with the pump, and can't be purchased by itself. So I turn to you all, for answers. If anybody could shed some light on this, they would be awesome forever.

Fabrik8

Have you looked around at places that sell both? Then you could just return the pump you just bought and then buy the whole assembly you need..

HatefulMechanic

for some reason I feel nice today.

You need what is called a fuel pump hanger. Call a local NAPA and have them order you a STP FG38A, it should be correct for your application. I highly doubt they will have it in stock, but it will only take a day or so for them to get it.

actionpaintball

You only need to replace the potentiometer switch on the pump assembly if it cannot be fixed:

After you make sure your wiring and grounds are good, double check them again...seriously; the switch works by supplying your gauge with varying voltage as the float moves up and down, if your ground or "voltage in" is bad to start with, your gauge will never be accurate.

9 out of 10 times you can fix the switch in the tank by gently bending back the tabs and simply cleaning the internals of the switch (WD40): gas tank condensation corrodes the switch over time. I just did the same fix on my '89 corvette which probably has the identical switch.

The switch is the pivoting mechanism that your float arm is attached to.

Believe it or not, some people have also successfully fixed sending unit issues by using Techron additive a few times (never tried it personally)

Fabrik8

If it's just a minor corrosion problem, there are all kinds of ways to fix it. Really fine sandpaper, ScotchBrite, a glass fiber pen, all sorts of things will work. Most of the sending unit problems I've seen are problems with the sending unit contacts wearing through, so there isn't actually any conductive material left. I haven't screwed with Ford sending units though...

HatefulMechanic

Generally the wiper contacts are worn out or broken off. Its thin gauge steel contacts that rub over a resistor, or in the GM case, a Mylar strip lol.

The float is likely trashed already, the brass floats Ford loved to use liked to fill up with fuel and cause a reading issue. The wiper contacts are usually worn out with the age. My suggestion of replacing the pump hanger is the best repair.

Unless you like to perform the same repair over and over again. Then, by all means, pull it out, clean it, and reinstall it.

From my standpoint, customers do not like having to see something be redone because the tech did not fix it correctly.

As for the Techron suggestion, that works mostly with the Delphi style units that are problematic on most GM's from 98-05's. Still, the replacement units that were offered (you can get just the sending unit instead of whole pump module) had gold plated contacts that worked MUCH better.

masterf99

So this Fuel Pump Hanger is the part that is going to have the new float and such attached to it, then I can attach my existing fuel pump to it and, (provided everything else is working properly) my problem should be solved. As for the wiring and such, I traced it all back to the guage cluster by hand with a flashlight, found no cracks, kinks, breaks, etc in the wire. I also metered at the plug on the top of the tank, and using the wiring information in the Haynes manual, I have the correct voltage at the plug, and the ground is solid as well. I'm really hoping this is the solution, cuz i'm about at wit's end with this thing. As always thanks to everyone that posted, i'll let you all know how it works out!!