Thread: New 130 owner - need air con

Well after much stuffing around, I finally dropped Jaffa into the Auto Elec today to have a Red Dot 6100 fitted. He is indicating that sorting out the 'idle up' will not be possible, unless I can provide him with details of how to achieve it.

Originally Posted by justinc

There is an input for A/C compressor load, not sure what ECU pin it is, but RAVE should show you. All you need to do is link signal in from A/C compressor feed to allow idle up when compressor is engaged, and activate 'A/C fitted' in the ECU settings. JC

Is there any chance someone can help me explain to him how to do this. I've had a look in RAVE (see extract below) but I can't work it out. So based on Justins advice, I need to know

1. What is the ECU input that tells it the compressor is on?

2. How do I tell the ECU that AC is fitted so that when the compressor is on, the ECU manages the engine accordingly (ie. idle up when AC on and whatever else it does).

RAVE "The ECM receives 2 inputs from the air conditioning system. The trinary switch (C0279-3) provides an input to the ECM (C0658-9) on a black/slate then yellow/slate wire. This input is the aircon clutch request. If granted the ECM provides an earth for the compressor clutch relay. Current can now flow from fuse 10 of the passenger compartment fuse box, across the energised compressor clutch relay (C1268-30 & C1268-87) and supply a feed to the compressor clutch (C0182-1) on a black/green wire. The compressor clutch is earthed (C0182-2) on a black wire.

The second input to the ECM (C0658-23) is the fan request from the air conditioning unit (C1273-1) on a white/black then purple/black wire. This causes the ECM (C0658-4) to earth the cooling fan relay (C0019-86) on a black/purple wire. Current can now flow from fuse 10 of the passenger compartment fuse box, across the energised cooling fan relay (C0019-30 & C0019-87) and supply a feed to the condenser fan (C0280-1) on a black/brown wire. The fan is earthed (C0280-2) on a black wire.

With the ignition switch in position -II-, the main relay (C0063-87) in the engine bay fuse box is energised and provides a feed to the compressor clutch relay (C1268-85) on a brown/orange wire. The earth path for the compressor clutch relay (C1268-86) is controlled by the ECM (C0658-29) on a black/slate wire. "

So I'm thinking the Red Dot Unit will have a feed that would normally go to the compressor clutch. This should be redirected to the air-con clutch request in the ECU ie. Pin 9 - hopefully this can be picked up via the black/slate or yellow/slate wire in the connector inside the fuse box. The compressor clutch relay should get its positive from the main relay in the engine bay controlled by the ignition switch, and then the earth of the compressor clutch via pin 29 on the ECU which I should also be able to pick up in the brown connector inside the fuse box.

Have I got this right?

Please please please help.

Tim

Below is a picture of the AC electrics - but I don't really know how to 'read' this. I do note that it shows the ECU and there are some numbers - perhaps representing the ECU pins? This may help someone with the right skills???

No longer needed, post above edited.

Sorry haven't been around much, so all sorted then?

JC

Thanks for following up Justin.

This is the advice I've provided to the auto elec (below). I'm still not sure it is right, but was the best I could figure out.

The "AC on" feed from the Red Dot 6100 can go into Cavity 3 of the brown connector in the fuse compartment in front of the gear lever, this will tell the ECM the AC is on. The ECM will then provide an earth for the Compressor Clutch relay (if present). The only thing I'm not sure about is where the feed from the compressor clutch relay emerges in the engine bay, and I haven't been able to find a picture of the connector that the original engine bay AC harness connects in to. Hopefully you'll be able to poke around using the section of the 'harness installation' section (from point 5) of the instructions previously supplied.

The outcome we are seeking it a feed from Cavity 87 of the compressor
clutch relay to the Cavity 1 on the compressor connector. Cavity 2 will
need to be earthed.

Hopefully that will be all the ECM needs to manage the engine
appropriately when the AC is on (ie. idle up)

Confirmation of this as 'good advice' would be appreciated, as well as any advice on locating the feed from the compressor clutch relay in the engine bay.