GMC Repair: GMC yukon wont start, crankshaft sensor, intermittent faults

Question
When it is humid or raining, my yukon won't run. As soon as it dries up, it starts, no problem. When I'm having this problem, it starts, runs a few seconds, then shuts off. I think it may be the anti-theft system cutting the fuel off. The dealer doesn't know what the problem is. What can I do? Thanks  

Answer
Intermittent faults are very difficult to find. Is the vehicle displaying a check engine light on the dash and if so, You need to find out what CODE is being stored in the computer via a scanner.

It COULD BE a lot of things and GUESSING can be very very costly.

The most common faults are caused by moisture getting into the CRANKSHAFT SENSOR wiring connector or into the ignition module connections or various other electrical connectors.

When the fault occurs you need to determine if you have a loss of FUEL, IGNITION to the spark plugs or ignition to the injectors before any diagnostics can be performed.