I've read a lot about repairing a suspect idle speed module by resoldering cold solder joints or bad connections within the module. I pulled mine ('91 420 SEL) and removed the cover. While I don't see anything obvious needing resoldering, are there particular connections I should be looking for? There are 2 circuit boards and my guess is the pin connections to the larger one and the pin connections between the boards are most likely. Anyone know if that's right?
Also, if I screw up, will the car still start and run (albeit with very high idle) without the module connected?

J.Chip