The exquisite, leather-covered power bucket seats offered by Cadillac for their Catera (a re-badged Opel Omega; the same platform was also later used for the Pontiac GTO) are a great value for the streetrodder. From 1997-2001, about 95,000 were sold in the USA. The leather seats feature 6-way power (driver and passenger; some are heated) and are made by Recaro. These are some of the most comfortable seats I've ever sat in and are frequently sold on eBay for $350 a pair .
Really? Just $350 for a pair of such nice seats? Why are they so relatively inexpensive?
The passenger seat is a conventional power seat with conventional relays and wiring. Wire up +12V and a ground and you're good to go. But the driver's seat uses solid-state relays and is connected to the car's main computer. As a result, many people believe that the seat won't work unless it's installed in a Catera and hooked up to the car's main computer. They are wrong.
All you lose by not being connected to the Catera's main computer is the three memorized positions that the main computer can store. Still, many people could not get the seats to work. The secret is all in the wiring, but the solution is hidden in the Troubleshooting section of the Cadillac service manual.
First, there are three +12V connections: two thicker wires and a thin wire. The thicker red ones (#1 & #3 in the service manual) are connected to an always-powered source. The thinner red one (#4) is connected to an accessory-powered source. The brown wires (#2 and #5) are the grounds. The data control wire is #6 and is not used. The secret wire is #7, a thin grey wire. In the Catera, this is connected to the door switch that controls the courtesy lights. When this wire is not grounded (when the door is open), the seats will not move. I just grounded it permanently; it seems the GM engineers did not want you to move the seat with the doors open. It's also important to wire #4 to a circuit that is hot only when the engine is running or it will drain the battery. That's all there is to it.
There are only two drawbacks to these seats. First, the Catera was four-door car, so these seats will not fold forward. If you used them in a two-door car, you won't have access to the rear seats. Second, they are wide, so without some modification to the seat cushion and re-covering, they are not usable in most 30's-vintage cars.
But if they fit (or can be made to fit), you will have some sweet, comfortable Recaro 6-way power seats for your ride for just $350.
For wiring information, visit your local Cadillac dealership, explain what you are doing and ask to see their service manual for the year of manufacturer of the car the seats came from. Then find the technician diagnosis section for the power seats. That's how I found the info for may seats.