02 express fuel pump voltage issue

[solvaysam]

Does anyone know why I would only only read 5 VDC on the plug connection of the fuel pump. There is no corrosion, using a good fluke meter, fuse and relay are good. I was told by the service tech at a chevy shop that there should be 12 VDC at the plug. Any ideas?

[MT-2500]

Originally Posted by solvaysam

Does anyone know why I would only only read 5 VDC on the plug connection of the fuel pump. There is no corrosion, using a good fluke meter, fuse and relay are good. I was told by the service tech at a chevy shop that there should be 12 VDC at the plug. Any ideas?

Yes the gray fuel pump wire should have battery voltage 12-13 volts.
Why are you testing voltage?
Fuel pump not running or putting out pressure?

Go to fuel pump relay and check for battery voltage into it on orange wire and gray fuel pump feed wire out of relay.

A problem are on fuel pump wiring is the fuel pump wire plug-in at the transmission cross-member.

If good battery voltage at fuel pump relay trace and check wiring from it to fuel pump for where it is losing voltage.
And check the cross member plug-in real close.
I have had to jumper around the transmission plug in a lot of times.

Let us know what you find.

[mufflersnmoretx]

We have no power going to the relay on and 01 express. Where should we start looking? We have no power on the orange wire to the relay or the grey wire to the fuel pump. Does the power feed from the ECM? or somewhere else?

[MT-2500]

Originally Posted by mufflersnmoretx

We have no power going to the relay on and 01 express. Where should we start looking? We have no power on the orange wire to the relay or the grey wire to the fuel pump. Does the power feed from the ECM? or somewhere else?

You need to start your own New thread and give van and engine size.

I would look in fuse block at ECM fuse-b.
Powers relay and PCM.