Hello Brokencase,
I checked the power to the antenna interface module and all is well. Your EVTM diagram is interesting, yours is on page 94 and my 1988 version (March '87 edition), has it on page 107.
Hello All,
I tested my FM antenna amplifier today but before I did I ran some basic tests using a distant / static compromised FM station;
1. Unplug / reconnect antenna cable plug at stereo housing - no difference.
2. Unplug / reconnect DIN amplifier connector and electrical connector below it - no difference.
3. Connected FM signal amplifier - no difference. *
* This was a long shot as ideally you want to amplify the signal as it leaves the antenna. Unfortunately this isn't possible with the Scorpio antenna interface unless someone out there has a schematic AND it is possible to modify the circuit. But at ~$10 for the FM signal amplifier it was worth it as a 'test tool'.
So .... the only conclusion I can draw from my repairs and tests is that replacing the two capacitors in the antenna interface module is the only change that improved radio reception. NOTE; I did not test AM reception as we never use that band, nor did I test with the rear window defogger on.
Hope it helps.