Got it. These two are changes between the ECM and PCM.

Condenser fan relay (PCM input)
B+ votage applied to pin 18 from condenser fan motor relay; when PCM switches on its power transistor, condenser fan motor relay coil is energized, causing current to flow in the circuit

A/C Switch 2 (PCM input)
B+ (A/C load high) to V<=1v (A/C load low); PCM receives signal from automatic compressor-ECU (pin 3) and determines idle-up speed according to high/low air conditioning load

Waiting for my '99 service manuals to clarify if this is valid for '99 or only '00-'04. Getting tired of borrowing the shop's set and sitting in their waiting room for hours going through one page at a time.:)

Still have to figure out what if any of the A/T stuff is present in the PCM and what to do about that. I have to wait until vol2 shows up. Dealership is missing that one so I haven't been able to go through the wiring diagrams - they all live in vol2.

If I never see another service manual again after this it'll be too soon. <img src="/forums/images/graemlins/shiner.gif" alt="" />

For thems who care, DIYAutoTune.com makes an ECM break-out-box. Their list isn't teribly accurate so they probably have a PCM box, too. Anyway, I thought it was interesting.

DIYAutoTune.com DIYBOB

Griffin is supposed to ship my new radiator on Monday and I'm picking up a new A/C condenser this weekend so, ... one step further along.

Edward