As I posted before, the circuit breaker in my Enginer started tripping after driving for 5-10 minutes. I managed to reproduce this with my car parked with the PHEV on for about 1/2 hour, carefully monitoring the current through the breaker, which averaged about 60A. When it did trip, I felt the breaker and it was very hot, so something was wrong. Yesterday I received a replacement breaker from 3ProngPower and installed it. It's working fine again today. When I removed the old breaker I noticed that one of the wires had about 1/4" of its insulation clamped in the breaker. One theory I have is that this was taking the pressure off the wire itself, causing a bad connection that eventually caused overheating. Another thing I noticed is that the wires were tinned with solder. This is commonly done in low-current circuits, but is this wise in a 60A connection?
Your theory above is absolutely correct. The insulation was preventing a good, solid electrical connection, resulting in the overheating. Tinned solder is never a problem with any electrical connection. My guess is that if tinned solder was used anywhere around the batteries it was to help prevent corrosion from the battery gases, which is a good thing.
