93 Explorer hisses instead of turning over

[bytebelle]

ok, here's the deal. I'm new, and I'm a woman who is very vehical ignorant. I have a '93 Ford Explorer with a new fuel pump and new/rebuilt computer. When I can get the vehical to turn over, it runs great. However, when I can't get it to turn over, there is a hissing sound near the "power relay?" just to the right of my sparkplugs. There is a red component that this power piece plugs in to. (I apologize...I work on computers not cars....) It does not have a tight fit, and I'm wondering if this is causing the fuel pump to keep the vehical from starting. I'mn not sure of the best way to add some pictures of the part I'm talking about.

 

[bytebelle]

Pic of part I'm talking about

 

[Kevlar7R]

im certainly no expert on your motor (would you mind clarifying what motor you have?) but that looks like a camshaft position sensor to me. I can't imagine how that would hiss.

Are you sure that the hissing isn't instead the sound of lots of current being drawn through the power cables, like the sound of a shorted wire?

Is it possible the sound is coming from the part above that, the coil pack? That coil pack is basically a big transformer, like the power supply in a computer. Have you ever heard a short transformer in a computer power supply?
When it won't turn over, does it make this hissing sound when the key is in the on position, crank position, or both?

Do you hear any clicking from the starter or relays before the hiss?

 

[bytebelle]

When I turn the key to the on position, I can hear the hissing sound. If I turn the key all the way, the motor tries to turn over, but it makes a sound like your just don't have enough power to crank it. Basically it just werrrrrrrrrrrrrrs.

It doesn't sound like a short in a wire. I'll check to see about what motor I have.