Ecm work around for a/c D1

[OklaIan]

I’ve got a 98 D1 that I converted to 300tdi/R380 a little while back. When I did the conversion, I didn’t plan on reinstalling a/c.
Now that it’s hot, I’ve changed my mind.
When I did my engine conversion, I blindly chucked my ecm and related wires.
I’ve been looking at the Rave ETM and see that the ecm sends ground the a/c clutch relay.
Is there a way to use a relay to do what the ecm originally did?
I’m not a wiring expert, but I’m not scared to try either.
If I’d paid more attention prior to the conversion, I would’ve kept the ecm solely for a/c.

Thanks
Ian

 

[fishEH]

Isn't it just a matter of hooking the "snowflake" button up to a relay that engages the AC compressor?

 

[OklaIan]

If it were that simple, that would be great.
From what I’ve read, the ecm provides the ground for the a/c clutch circuit.
Thanks
Ian

 

[fishEH]

If it were that simple, that would be great.
From what I’ve read, the ecm provides the ground for the a/c clutch circuit.
Thanks
Ian

Ground is a ground. Make a new ground. The compressor is stupid. Its doesn't know nor care what its power source or ground point is. Pretty sure the compressor is a 2 wire hookup, power and ground.

 

[ERover82]

No AC expert but I believe it cycles on/off based on evaporator/condenser temperature to avoid freezing and possibly other conditions.

 

[DiscoPhoto]

I never did it on my 300 conversion because it was above my skill level(Im terrible with electrical work), but the person that bought it from me had it working in like a week or two.

 

[fishEH]

No AC expert but I believe it cycles on/off based on evaporator/condenser temperature to avoid freezing and possibly other conditions.

That makes sense. I forgot about that...

 

[OklaIan]

From what I’ve read in the ETM, the a/c clutch relay has power as soon as the key is turned on. Then when the a/c and fan switches are on, the ecm sends ground to that relay.
Seems like maybe i could just add a switch to ground the relay. That would make turning on the a/c a three switch operation.