The gremlins have settled into my electrical system!

OK, I have a 1997 Saab 900S automatic with about 122k miles on the clock. This problem has me stumped. It started in the summer where if I turned on the heated seats the: windshield wipers, electric windows, ventilation fan, directional indicators, cruise control and rear defrosters fail. They just stop functioning. If I turn off the seat heaters and those components listed above (those which were turned on at time), they all come back after a few minutes (immediately comes back if I shut the car off and restart it), except for the cruise control. The cruise control can come back in 15 minutes to a few days. Even that coming back seems to be influenced by me, if I push on the brakes the cruise light comes back on, though when i set the speed to use it, it fails again. So I replaced the battery and this seemed to solve the problem for about a month. Once that month was up the problem showed back up. If I had the seat heater switch turned from a prior trip and start the car all the items listed would be inoperable right from the start, and follows the same reoperational time above. Now its become much worse. I was driving the other night in heavy rain with only the ventilation fan and wipers on and midstroke the wipers and fan failed, shut the vent fan and wipers off and a few minutes later they came back. Then tonight while driving home again in the rain with the wipers, vent fan and rear defrost on I lost it all again, along with all the dash lights and all the exterior lights (including headlights, that was fun in the dark. So again shut off the wipers, vent fan and rear defrost and everything came back again, thankfully, engine performance was NOT effected by this electrical failure, radio was uneffected too. I'm at a loss to figure out what is going on.
So in summary:
1.) I lose power to certain bits of electronics when I put a load on the electric system.
2.) Resets itself after a few minutes once all switches to components are shut off, or if I restart the car.
3.) Problem growing.
4.) All relays and fuses are seated properly.
They only common electrical grounding point I could find is a point behind the battery mount and to the transmission. I did a quick cleaning of the transmission grounding point, but will try to clean it better tomorrow, and I reseated all the relays I could find under the hood. Does anyone have an idea that doesn't involve paying the stealership? Does this sound like the death of the ICE (integrated central electronics) unit? I did read a TSB for the 94 where the ignition switch's electical contact does quite rotate all the way to the full power position, and requires lubricating, but that was for a 94, and their is no mention of that TSB for the 97, plus the radio keeps function properly. Any help would be very appreciated. Thanks!

My first, uneducated guess, would be that the top was down at some point in the past and the car was rained in.

If not that it could be a computer. I once had a computer go on my Chevy truck and it was very hard to trace that one down. Once I replaced the computer the truck was perfect. The symptoms were kind of the gremlin thing. If I were in your shoes I would find a good foreign car repair place, non-dealer, and let them fix it. When confronted by a job that I don't feel like dealing with I take my cars (SAAB and Volvo) to Foreign Accents in Greensboro NC. I have always been pleased with the work they do and I have never been screwed. Your problem sounds like it might be more than a shade tree mechanic ought to deal with.

Its a hard top, so no rain has gotten into the system. Did have a weak battery the other day when it got down to 9F the other day, went to Auto Zone and had it load tested. It failed. Luckily I had bought the battery at the same place 5 months ago so I got a new one free. Problem still exists. I pulled heated seat switch out and checked for ground continuity while the engine was off, which is showing ground is good. Only getting 11 volts thought at the switch, possibly a short? I think I'll try again tomorrow morning with the engine running.

Have you checked the alternator? The same thing happened to my 1998 900 S and it was the alternator. Just so you know the idler wheel had to be changed also because the bad bearings were making the pulley slow the belt down.

you might want to check all of the car's grounds too while youare at it. ther are many under the dash and a few important ones on the right side of the dash next to the glove box. check and tighten all engine groundstraps and ground wires. i have seen alternators cause some weird problems like that. if you had to replace 2 batteries in 5 months, there is definitely a problem, maybe with the charging system.

Just to throw in my :2cents:, I'll go ahead and suggest that you also check your battery cables for good connection or corrosion as either of these would cause improper charging of the battery (smearing some Vaseline on the connections will prevent corrosion and insure a good connection).
One other suggestion would be to check the trunk's boot light to make sure that the three-way switch is in the "off" position.

Just to throw in my :2cents:, I'll go ahead and suggest that you also check your battery cables for good connection or corrosion ans either of these would cause improper charging of the battery(smearing some Vaseline on the connections will prevent corrosion and insure a good connection).
One other suggestion would be to check the trunk's boot light to make sure that the three-way switch is isn the "off" position.