1998-2006 Yamaha F20/F25 Outboards Service Manual, Page 377Get this manual
ELECTRICAL ANALYSIS
When measuring the peak voltage, connect the peak voltage adaptor to the digi tal tester and switch the selector to the DC voltage mode
Make sure the adaptor leads are properly installed in the digital circuit tester Make sure the positive pin (the "+" mark facing up as shown) on the adaptor is installed into the positive terminal of the tester The test harness is needed for the following tests