-30 = constant [positive (+)] power (usually wired directly to car battery)
-85 = coil ground (wired to the negative (-) battery terminal or any grounded metal panel in the car)
-86 = coil power (wired to the control source. could be a switch, or it could be the car's IGN or ACC circuit.)
-87 = switched [positive (+)] power output. (when the relay coil is powered, lead/pin 87 is connected to lead/pin 30)
-87a = [on 5 lead/pin relays only] this lead/pin is connected to lead/pin 30 when the coil is NOT powered.
The wiring from my understanding looks good. Where I am getting confused at is with the Hobbs switch, I assume this is going to be boost activated to turn on the second pump, but don't see how in your wiring diagram.
Any other information will be helpful as I plan to do this same thing soon.
__________________
Hopefully not to much longer. Complete Rebuild will bring color back to its life.
The wiring from my understanding looks good. Where I am getting confused at is with the Hobbs switch, I assume this is going to be boost activated to turn on the second pump, but don't see how in your wiring diagram.
Any other information will be helpful as I plan to do this same thing soon.
I *think* this is how the relay works. When the hobbs switch sees 4 psi, the switch closes. when this happens, the the pump gets the voltage. I could have this terribly wrong and suck at wiring so i would greatly appreciate any help.
__________________ 2002 NBM Firebird Formula D1sc, EPP Fmic, built 347ci, Ls6 cam, Ls6 heads, Alky Control Meth, Kooks Headers with Cats, Magnaflow, T56 swaped, McLeod Twin Disk, HPTuners, Shaner S3, BMR LCA's, BMR PHR, 6 point wolfe and Corbeau CR1's. 480rwhp@7psi 11.217@121 1.64 60ft (stock motor)
Now Tuned by EFI Alchemy 584RWHP 532RWTQ 2006 TBSS Borla weld-in, IEATSRT8, HPTuners, E-Fans and tranny cooler
Twin Intake Wiring Diagram 
