Just bought 2001 s40 heater blower surging replaced resistor still doing but not as bad, i read somewhere about soldering something but couldn't find details. Also rough idle at start up no gas leaking into vacuum line. any help would be greatly appreciated.

 

Your rough idle could be a sticking IAC valve. It is right on the front of the engine and only has two torx bolts. Remove that and take care not to damage the gasket either. Use some electronic parts cleaner. You can find it at any auto parts store. Just spray the crap out of it and let it soak in there. Be sure it dries completely and then put it back on. It doesn't always work, but it is much cheaper then buying one for $150, and it is a good place to start when having a rough idle.