i put a PMS in yesterday, and am not sure how to wire it to control the vtec crossover. it has 3 accessory controls, which basically provide a switched ground. you can tell it what RPM and/or Throttle Position are required to engage whatever feature it is controlling.

so........ what do i connect to what?

i gather from the helms that the vtec solenoid engages when it sees battery voltage. since the aux output on the PMS is providing ground, would i want to use a relay here?

i take a 30 amp 4 wire relay, connect one pair of terminals to 12v and the pms aux output, and then the other pair to 12v and the vtec solenoid?

tia.

 

Since the PMS provides a pull to ground and the VTEC solenoind requires 12V to engage, you need to wire in a standard one make, four pin relay. Supply voltage to one side of the coil and wire the PMS to the other side of the coil, then run one side of the switched side to 12V and the other side of the switched side to the VTEC solenoid. Very simple, I had to wire in relays for all my stuff that the Haltech controls (VTEC, fan, etc..) Good luck.

 

right! that's what i was figuring. thank you.

is there any danger totally disconnecting the stock ECU from the solenoid? i was planning on just cutting the wire at the ecu and wiring the relay in down there. no problem tapping into the 12v source for the ecu or multiplex controller, right?