Got your PM.
Mine is an off brand cheapo I found on eBay or some such. Truth be told, I rarely use it.
I use a jumper in the test connector, sit in the seat, and watch the engine light. Several reasons. First, if in a noisy environment you may not hear the beeps. Second, in the KOER, there is a WOT and a BOO. You have to be in the cab to touch the throttle and the brake at the appropriate times. Third, multitasking; listening for the beeps (engine and shop noise), while watching the led, while writing...
When I do use it, I run jumper wires from the test connector though the passenger door, to the test unit in the riders seat. This way, I can hear the beeps, while seeing the light, and do the WOT/BOO.
The true tip: You have to have the CORRECT code sheets. OBDI allowed different meanings for different codes, depending on make/model/engine. It is not so bad with Rangers but there are some gotchas. If you can get a correct sheet, use it. The generic sheets can lead you astray.
Librum
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