Help! Relay wiring for IAB (Secoundary Butterfly) (-)output!

[gherrera]

Good day everybody,

This is the question that never end, I know but I can't found a reliable way of wiring the IAB solenoid.

I have a P28 with S300, first try I follow the wiring diagram of VTEC relay for non-vtec ECU, thinking it works as same with the IAB solenoid, but never works with this setup.

Then I follow the troubleshooting guide of Service manual for the IAB system, I turn the Ignition ON and check for voltage between Pink and the Black/Yellow wire, I found any voltage but the relay activated well, after that I checked the voltage between pink and chassis I found voltage then did the same with black/yellow and Surprice!, also found voltage there.

Reading the service manual, the pink wire must be a negative output, well the tradicional way to wire relays as negative outpu did not work because the trigger is a negative output (PIN A15 ACC (Air Condition Cluth) from ECU.

My wiring for the relay is;

The first try as VTEC diagram; 85 = A15 ACC Output , 86 and 30 = positive ACC , 87 the pink wire to wiring harness.

The second try, tradicional Negative output; 87 and 86 = chassis ground , 85 = A15 ACC output , 30 to the pink one

Really apreciate someone help me to wire the right way.


saludos from Panama!

[Spunkster]

What year vehicle is the engine from?

[gherrera]

What year vehicle is the engine from?

Prelude 92 96 H22A OBD1! (FYI... I did try the Invert IAB output, but nothing happen, the relay is working well I checked it, I think is somthing about the relay wiring for the (-) output)

thanks for u replay!

[Spunkster]

You will have ot check the hemls manual for that year engine as some years the secondaries are ground activated and other years they are power activated.

[gherrera]

You will have ot check the hemls manual for that year engine as some years the secondaries are ground activated and other years they are power activated.

Right, IAB´s Prelude over 97 OBD2 are powered by (+) output

for 92 96 are (-) output