No way to bypass a bad solenoid. A and B are the same. There's also one for the torque converter lockup. They're all in the cover at the front - and they are NOT easy to access. Total PITA. I believe several of our vendors sell them - I would call around for the best price. Give Tasca parts (just g...

I almost want to do this for fun. I replaced the heater core on my wifes 740 last year. It took all 12 hours. Eight to disassemble the underdash and just about everything else in the front of the car. Four to put it back. Then the plastic capped core only lasted 6 months before it blew up.