I think 850 or so would be great. He can find the problem and get there if he isolates one system at a time and eliminates each individual thing in that system. It's called a diagnostic flow chart and I am very familiar with them working in dealerships for years. Jumping to other systems while trying to diagnose one and you may never find the problem. Following a flow chart seems slow, but it's dead accurate and he will find the issue. Well......he would have.
