Turbo E

okay, the compressor relay has 4 wire leads.

1) White 12V+ constant on (from underhood fusebox)
2) BK/Yellow 12V+ ignition on? (blower motor relay)
3) Red power to compressor (powers compressor)
4) BK/Red to ECM/CPU (ECM pin A15)

so...

#1 self explanatory
#2 seems to be on contsant when ignition is turned on
#3 when 12V+ is applied, the compressor clutch engages.
#4 I don't know what this does. I stuck a test light into it (at the main wire harness side) and the compressor clutch engaged??? also the test light lit up, so its a 12V+. When i stabbed the wire near the relay, nothing

is #4 a 12V+ signal to the relay to close and power up the copmressor? Is it intermittant? (dependant on cabin/AC temp?)

at any rate using the OEM relay doesnt work so I wired it up like this:

1. relay switch is powered by tapping the condensor faN 12v+. Fan goes on, compressor runs. fan stops copmressor stops.

2. ground it to the chasis

3. 12V+ in - constant goes to one lead on the (aftermarket) relay

4. 12V+ out - goes to the compressor power.

should i use another source for the relay switch power (#1)? like #4 which i suspect is a 12V signal wire (not constant)

any input is appreciated.