1996 Fuel Pump Wiring Diagram or Test Power to Pump

Does someone have a wiring diagram for the fuel pump circuits on the 1996 Tacoma (4 cyl)? The fuel pump is not working and I need to find out if power is going to the pump. I found the plug where the wires connect to the top of the tank, but I cannot see it well enough to tell if there is a way to unplug it without lowering the tank.

I downloaded a copy of the factory repair manual, but I could not find a wiring diagram for the fuel pump circuits. It looks like the 1996 wiring diagrams manual is out of print. The DLC1 Data Link Connector has a slot for the wire that runs to the fuel pump, but it is empty.

My Tacoma has been sitting for a few years. A mechanic warned me that the fuel pumps often fail when they are not used, but I want to make sure that power is going to the pump before I remove the tank.

Thanks for any help or suggestions,
Lloyd

 

@mechanicjon

 

it is a simple circuit, the White with black tracer is the ground, the Blue is the +12 volts in. The Blue is only energized when cranking or the engine running.

The White with red tracer off of the data link connector is powered from the EFI relay throught the 7.5 A IGN fuse. it powers the heater circuits of the O2 sensors, the Mass Air flow sensor etc.

 

Yes?
You need something like this?

 

I'm pretty sure OP needs it more than me

 

mechanicjon,
Thanks very much for the diagram! That was exactly what I needed. Also thanks to Glamisman, although I did not understand that post until I saw the diagram. I found the Circuit Opening Relay and was able to measure the voltage there. (I would never have guessed that the relay controlling the fuel pump would be given such a non-descriptive name.)

In case anyone else reads this thread in the future because they have the same problem, I want to describe how to unplug the electrical wires on the top of the tank. I do not have much previous experience working on Toyota products, so I spent about an hour gently poking and prodding at the plug with various screwdrivers trying to get it to come loose. I finally got it lose, but I ended up breaking it.

The plug is removed by simply pulling up on the plug while releasing a single catch in the side of the plug. It looks like a small screwdriver is needed to release the catch, and very gentle force is required to keep from breaking the catch. The plug comes off easily after the catch is released.

From examining the plug, I expected the cover over the wires on the back of the plug to open on hinges so that the plug under it would then be released. That cover over the wires on the back of the plug is permanently attached, even though it yields to gentle pressure.

Lloyd

 

I know this is an old thread but I'm trying to figure out how to run the fuel pump without the engine running (finishing up a rebuild and need to empty tank of old gas).

Looking at this diagram, would it be correct that I could remove the COR and jump the white/red wire to the blue wire to run the pump? Id really appreciate some help from someone who understands this better than me. The last thing I need is to mess up some electrical components right now.

 

yes that would turn the pump on.

 

Thank you. This info will save me the work of pulling the tank on a 2wd with about 10 gallons of gas in it. I was not looking forward to that