Thunderbolt V base setting for ignition

[DerekB]

Hello , I’ve a Maxum 2900 with twin 4.3 Tks engines
I’ve read umpteen web items of advice and downloaded an ignition section of a service manual that advises to earth the purple / white cable next to distributor to lock the auto advance while strobing the 10 deg basic setting , however my purple / white cable is fitted into a 2 pin base socket ( there is another cable also ) and has a ‘smart’ 2 pin plug that sits into the base socket for normal running ?
My quandary is how do you earth the purple/ white cable or is it that the plug in cap is the earthing device and you remove it for normal running ?
Hoping to get accurate guidance here

[mmwjr]

Can you post a few pictures?

[mmwjr]

From the wiring diagram in manual #24 there is a plug, purple/white that gets grounded to set base timing. This is a separate connector plug and not the one used by the ignition system. It may be near the distributor or front of the engine. The manual is located under Documents.