My 1984 El Camino blows the fan/ac fuse when engine starts. Thought it was a bad blower motor, took it out, lubed it, worked fine, can let it stay on for a long time with ignition on, works in all speeds, until I start the engine, then fuse blows immediately. What is different when engine runs? A relay somewhere? Have not got the original GM wiring diagrams and troubleshooting in the mail yet. I am more familiar with MoPar cars. Have tried to disconnect a/c, no difference. Anyone got same problem?