[dataway]

I noticed on the round, clip in, firewall AC harness grommet there was an additional hole above the main hole where the AC harness passes through ... anyone else have that, know what it's for ?

Also notice that the Radio Suppression diagram shows the blower power passing through an in-line capacitor just before it plugs into the blower motor. Not the typical capacitor connection to the power lead and grounded case .. this shows the capacitor INLINE on the power lead with the case grounded. Never seen that before ... is that an AM/FM only addition?

[OG68]

Yes. AM radios just ran the power wire directly to the motor. I would have thought the AM radio would require it more than the FM.

But back in the day, FM stations were few and far between and reception wasn't all that great. Maybe GMs way of improving signal quality.

[Verdoro 68]

Originally Posted by dataway

I noticed on the round, clip in, firewall AC harness grommet there was an additional hole above the main hole where the AC harness passes through ... anyone else have that, know what it's for ?

On mine, the top hole is for the vacuum hose for the A/C system.

[dataway]

Excellent folks, two questions answered with great efficiency

I did research them myself but could find no conclusive answers.