1993 Eldorado, 4.9L

On the backside of the rear seat support (i.e. accessible from the trunk), there is a block w/ 6 or 8 relays. Does anyone know what the relays control?

The Air Compressor for the ELC system has stopped running. The air compressor and its wiring are difficult to get to, so I'd like to knock off the easy stuff (i.e. confirm relay is good) before going in for the compressor. I had the height sensor out last weekend and had expected it to be a simple On/Off switch, however, it has 5 or 6 wires coming out of it and I have no idea how that thing works. The fuse is good. No codes. The Compressor's connector is too buried to supply 12v directly to it. Does anyone know if the Air Compressor's relay is on the backside of the rear seat support?