hot fuel module

[Marc Piccioni]

The '88 chev van 'G' that donated its wiring harness and fuel pump has a 
module that my local GM dealer can't figure out what it is. From tracing 
the wiring I believe it is a "hot fuel module" or at least that is what my 
non-GM wiring diagrams call it.
 It has 3 wires - 1 to +12, 1 to gnd. and 1 to the fuel pump hot side.

Does it maintain fuel pressure if the ambient temperature is above a 
certain temperature to prevent vapour lock  or ?????????

/Marc