Ok, I'm a newbie here, but just bought this immaculate '96 F-150 XLT 4x4 and love it. It's a perfect match for my '97 Harley Wide Glide:



I've been turning wrenches on vehicles since the early '60's, when my first car was a '51 Ford Crestliner and my next two were '66 and '68 Mustangs...then Harley's, other motorcycles, tractors - you name it.

My new-to-me F-150 only has one problem where I need some help. When I switch to the front tank, the fuel gauge doesn't work. Fuel pump works fine - I just don't know how much fuel I have.

Being an electrical contractor for over 40 years, troubleshooting/fixing electrical problems is something I do in my sleep. Normally.

The electrical schematic I have in the Haynes manual shows only the wiring for the fuel pump "Tank Selector Switch" in the dash, but no diagram of the wiring for the gauge. It shows this switch determining which fuel pump, front or rear, gets energized.

But nowhere is there a diagram of how/where the signal to the fuel gauge is switched.

I don't want to pull and replace the whole unit in the tank that houses both the sending unit (which may be bad) and the fuel pump - having to replace the whole unit. First I need to determine if the problem is in the wiring from the sending unit to the gauge.

Any help on this would be appreciated!

 

The selector switch switches the power to the pumps and the signal from the sending from the the tanks to the gauge.

 

It's the sending unit. You're more likely to find these trucks with gas gauges that don't work because it's a very common problem.

 

NH - To do this, the switch would have to be a double-pole switch; one leg switching power to the pump (larger amperage), and the other leg switching the lead from the float switch in the tank (very low current). The two leads cannot be the same.

I realized the problem is 99% likely in the sending unit, just want to eliminate other potential problem locations before pulling the tank and unit.

So you all are saying this is a common Ford problem in this series truck?

Any tricks for easily pulling the tank selector switch without pulling the whole dash apart?

 

Shouldn't take more than 5 minutes to pull the dash bezel.

Pop off the 2 silver spears and there is 1 bolt under each of them.

Turn on the headlights and use a small/tiny screwdriver to release the spring clip and remove the **** from the switch.

The Bezel is held on by a clip either side of the steering column and about 3 clips across the top. Just pull gently and the bezel is off.

EDIT:
Here is a pic of the location of the headlight **** clip.

 

Yes it's a very common problem with these trucks, and yes it's like a double pole switch.

 

 

THANKS BRO! EXACTLY what I was wanting....

 

Thanks, Don - once you know a particular vehicle, it's all easy. Just that this truck is new to me......

 

If the switch and wiring are good - which we all suspect they are - do you have to drop the tank to change the pump/sending unit module????????

I know the answer is almost certainly 'yes', but I know from a lot of forum experience on other vehicles (motorcycles mainly) there are geniuses out there who have figured out all kinds of 'impossible' things!

And I'm sure there are some of those here!