Is there a way to hotwire the fuel pump

[NJB]

Vehicle is a 1994 GMC Safari 4300 Vortec W code.

 

I want to be completely sure that the pump is bad before I replace it.

[BBSilverado]

Vehicle is a 1994 GMC Safari 4300 Vortec W code.

 

I want to be completely sure that the pump is bad before I replace it.

 

<{POST_SNAPBACK}>

 

 

 

Remove the fuel pump relay.

Make sure terminal #30 in the relay socket has power to it, then install a jumper wire into terminal #30 and into #87. The fuel pump should run then. If #30 has no power to it check the fuses.

[NJB]

Thanks, just to make sure...does the ignition have to be on?

[GM-Tech]

Vehicle is a 1994 GMC Safari 4300 Vortec W code.

 

I want to be completely sure that the pump is bad before I replace it.

 

<{POST_SNAPBACK}>

 

 

 

There's a fuel pump "test" or prime terminal. This is usually a single red wire with a black plastic connector and it's typically hanging out of the harness real close to the fuel pump relay.

 

Powering this lead up will send power directly to the pump, but it's wired through the relay so that it will only power up the pump if the relay is not on.

[GM-Tech]

Thanks, just to make sure...does the ignition have to be on?

 

<{POST_SNAPBACK}>

 

 

 

In the case of the "test" terminal, the relay will only be on for two seconds with the key on if you're not cranking over the engine. So this will work with the key on (after two seconds) or key off.

[BBSilverado]

Thanks, just to make sure...does the ignition have to be on?

 

<{POST_SNAPBACK}>

 

 

 

 

No, the ignition doesn't need to be on. The ignition normally powers the coil terminal in the relay (#86). with the coil activated it closes the circuit between 30 (battery power)and 87(power out to fuel pump), this is what your going to do manualally with a jumper wire.

[NJB]

Which is the 87 terminal, I know which one the 30 is.