1966 Rally Tach wiring harness
 

I'm trying to get my wiring as correct as possible. On page 15-14 of the shop manual it shows this round object. Is this just a grommet where it goes into the firewall or is this some sort of resistor or a rotator splint of some sort?
So far I really only have part of the brown wire that hooks into the back of the Tach and then basic black wire spliced in. I see a repro kit that has the wiring from the coil to a clip, but don't know where that clip goes according to the wiring diagram here

Depends on which tach you have. Ones with passive circuits are for points ignitions but the Delcotronic tachs (have seen for 65s) have an extra power lead.

If you scroll further down page one and see a thread on 10-26-21 there’s talk on the round grommet that’s used for the under hood lamp Black wire or the tachometer Brown wire.

Mine is the standard ignition. Thanks for the replies.

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Thank you for the pics. I'll search Ames for that part number. Ames is the best price I have found for the Tach wiring harness too.

I ordered the grommet from Ames along with the correct wiring and installed it. Everything looks great. Just found the original grommet at the bottom of one of my bins that I put all the parts in when I tore it apart a few years back. Same thing happened with the windshield wiper transmission clip. Searched and searched, ordered the replacement then found my original. Just had to share.