Saturday, July 23, 2016
Follow The Yellow Brick RoadPosted Friday, July 13, 2012, at 11:18 AM
What brings the above to mind is my recent "trip" through my factory Jeep's shop manual.
If you have never seen a factory shop manual, it really is a wonderful document filled with detailed information including drawings and diagrams that show where vehicle components and wiring connectors are located, the proper way to diagnose trouble with every vehicle component, and how to remove and replace any part of the vehicle. There are detailed instructions about how to repair wire connectors and splice wires as automotive applications are more demanding.
Diagnosis of problems is a big part of a factory shop manual. Electrical and mechanical systems are so complicated that detailed troubleshooting procedures need to be followed... hence the Yellow Brick Road analogy with the Emerald City being a completed repair.
After towing the Jeep to Arizona and back last winter, Blackie wouldn't start when we unhooked upon our arrival home. It was cold, I didn't need the Jeep, so I just pushed her into the Barn and decided I'd get around to fixing it later. Well later happened a couple days ago.
To follow the Yellow Brick Road, you need to start at the beginning...
I pulled Blackie out of the barn and moved her into the garage. I pulled out my Yellow Brick Road book and started trouble shooting the problem. All was going well until the Yellow Brick Road book pointed to a battery lead that was to have power when the key was turned on. Without power to the lead described, Blackie won't start. BINGO!
So the search for a bad component or loose connection begins. The manual has detailed electric wiring harness drawings that show where each and every wire physically is located in the Jeep, so finding a loose connector should be easy. Hmmm... a loose connector is not found and no bad components. I hit a dead end.
There is only one possibility left, a wire is actually broken in the connector where the Yellow Brick Road book first pointed me for testing. So I open up the connector and discover...
AAKKKKK! The Yellow Brick Road book was misprinted! The initial test point was not connected to the wire I was tracing! Battery and ground connections were reversed in the connector from the schematic diagram. It worked great except for troubleshooting! Close to 8 hours over two days of crawling around the Jeep, and I was little closer to Emerald City and solving the Jeep no start problem.
Those hours spent following the Yellow Brick Road book and inspecting the Jeep didn't go totally to waste. Since I had looked at the schematic diagrams numerous times, I quickly figured out a wiring shortcut and my starting problem is solved.
I guess my point today is it's true that if you follow the Yellow Brick Road, you may get to your destination, but there may be a few detours along the way.
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