Vehicle is a 1985 K5 Blazer. The windshield wipers work fine in the "Full On" position but do not work at all in the delay positions. I figured it would just be a simple matter of replacing the delay module at the bottom of the steering column, but I read elsewhere that there is a "box" of some sort under the hood that might be bad instead. How can I check these two items to find the culprit without just blindly throwing money at the problem and replacing both items at once? Or is what I had read elsewhere totally incorrect and it's just a matter of the delay module beneath the steering column having gone bad? Thanks in advance.