1995 Blazer Vin "W' 202,000 miles. Installed a Bosch Alternator to replace the OEM unit in 2004. I hear a static noise on the AM side of the radio that is akin to what the old generators would provide if there was no condenser attached to the unit. I contacted the technical department of Bosch who informed me that no condensers are required on these units and that GM does not require one. I have installed new oem type spark plug wires along with plugs, cap, ignition module, ignition coil, and had the VCMA reprogrammed. The Blazer will run perfect at times (with noted static) and then will surge or appear to cut out momentarily while driving. No DTC codes will set and the tachometer does remain steady even though it appears to be an electrical problem. Any ideas would be appreciated.