I checked the section numbers against my manual and it doesn't match up (there are two different versions of the manual out there, data is the same but it's arranged differently) so I don't know what P17 and A8 are. I assume the reading was intended to be taken directly across the two gauge terminals. After disconnecting the wires I read 55ohms. Noticing the values changing I rubbed the probe against the terminals and was able to raise the value to 70ohms. Not the 100 you mentioned. Bad gauge??? If I do need a replacement, then I don't know where to source one because I have yet to find somebody parting a genny out. Only option I know is to use the digital gauges off Ebay, but they read amps and not watts. Although amps might be more correct, watts is easier to understand.