OP, you said you replaced the combi valve and the SAIP (the pump/blower itself).
Beside those parts, the most common causes of SAIP system failure are:
Beside those parts, the most common causes of SAIP system failure are:
- The 373 relay in the ECM box that switches power to the SAIP--the contacts are rather small. Mine lasted 10 years. If yours hasn't been replaced, do it.
- The SAIP fuse (40A) in the ECM box.
- Vacuum hose between solenoid valve and combi valve. If it leaks, the combi doesn't open. The hoses kind of turn to plaster in their old age... See my DIY in the info base.
- Plastic hose from SAIP to hard pipe (but you would noticed that).