Weird bit of a problem on the '05 GMC Envoy yesterday. Turned the key to fire up, and I usually wait until the fuel pump primes before cranking. Soon as I cranked, all the electrics died - dome lights, instrument cluster, audio head unit. I couldn't even turn the key back to the lock position. The Motorcraft branded (BXT-78E) East Penn I got is only 2 years old. Popped the hood, checked battery voltage and it was 12.6 V, load test dropped that down to 10.1 V. But as soon as I touched the battery connectors, the lights came back on. The truck wouldn't start, and everything died again, but I had an 8 mm wrench on me, so I went ahead and tightened the bolts and it fired right up. Does this mean I just need to sand the contacts and replace the bolts (I have a couple in the box), or is this something else? Thanks!