Originally Posted by thefatkid
Resistance checks are really worthless in most automotive applications. A correct way of diagnosing a problem is using voltage drop tests. Measure from after the load on any circuit to the negative terminal of the battery. Any voltage over a couple tenths shows a possible issue on the ground side. A DMM does not load a circuit and does not provide any real valuable information.
Excellent observation Brian!
In fact, the best way to validate design and workmanship in a high current application is to measure voltage drop across whatever is suspect, whether it is a connector or a conductor. Especially suspect is the return as you mentioned. I like to use star washers on frame and body connections so they dig into any coatings, whether oxidation or residual paint after it has been sanded.