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Discussion Starter #1
Hi all! I am the new owner of a 1988 Ford Bronco XLT. My last Bronco a '79 was the best thing I ever owned, mainly because it was all mechanical. This thing however, has A LOT of electrical components on it that already seem to make my eyes go cross. Here's my issue that I need some input on:

The fuel level, with the engine off, reads at around 1/4 full, when I fire it up, the needle goes all the way past empty. I thought maybe a bad ground somewhere, but before I check it, I decided to fill up the tank and see if it would still read the level of fuel with the engine off and after doing so, the think still reads ~1/4 full, so I'm at a loss.

With a 3" body lift it makes it easy to get under the Bronco and inspect the fuel sending unit where its attached to the tank, I checked the connection there and was surprised to see how clean the connection is, it looks brand new. I bought a Hayne's manual to see if that might be helpful to my problem and obviously, its not. I was hoping to see if ya'll might be able to point me in the right direction to figure out how to get my guage working, it's the only thing wrong with the beast, and the one thing that I need, since I have no idea how much mpg it gets in the first place.

Thanks for any help, links, tips!

Premium Member
9,990 Posts
Kudos getting a Haynes Manual right away, so many don't but fill in more details under your registered user name, Bronco info: so everybody knows at a glance what's in the BKO to help make suggetsions.

Now, your Bronco is either a 302/5.0L or 351/5.8L EFI = electronic fuel injection so now you need to get familiar with the terminology and how things work together, homework assignment is to look up IAC, TPS, ECT and O2 sensors....these are fuel managers at cold start and normal operation that talk to the vehicle computer that you can actually "pull codes" from and diagnose what's going on but requires either an OBD-I or II Ford Code Reader with diagnostic book, costs $29.99, the vehicle test connectors are in the engine bay, mine are on the right inside fender liner behind the battery area, Red & Tan off the harness.

You can either test the dash fuel gauge for voltage issue using a multimeter or the fuel pump/sender unit in the gas tank but that's in a difficult location inside the gas tank so it would A. require draining and dropping the tank for test/replacement B. cutting an access panel in the cargo bay floor right above the sender unit area to test/replacement, much easier access but it's your call.

There is a section in the Haynes Manual showing the dash guage components so look that over and how to back probe.

Fuel pump/sender units usually run around $100.00 so you can either shop around for best price or $$$$pring for a better quality product like Motorcraft so it will last longer.

Additional Help: - How to "pull codes" and more ( aka: FSB member: Fireguy50 - owner Ryan McCormick
FSB member El Kabong's - baba loohey's favorite FSB links and questions
FSB member Steve83's - tech album, click on his black Bronco to take you to it then scroll.

Good Luck ~ :thumbup
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