International Ignition Switch Wiring

[AXett]

Working on pinning out the 4-wire ignition on my 08 International. This post is combo information and question...

I've got a BAT, IGN, ACC and STA terminals.

With the key out, continuity between none of them.
With the key in at the 10 O'clock position, there is continuity between BAT and ACC.
With the key in at the 2 O'clock position, there is continuity between BAT and ACC, as well as BAT and IGN
With the key in at the 3 O'clock position (spring start), there is continuity between BAT and IGN, BAT and STA, and then (surprisingly) not between BAT and ACC.

So everything here is as I would expect, save that when turning over the engine, it disconnects the ACC system. I'm guessing this is done to protect anything on the ACC circuit from possible voltage fluctuations during turnover?

Replicating this wiring will make installing a "hidden" cutoff key and a push-button ignition a little complicated, so I'm curious if anybody knows how necessary that disconnect of ACC when STA is engaged is.

Cheers!

[somewhereinusa]

Everything that is on when in the acc position should be on when switch is in the ign position.

[AXett]

Originally Posted by somewhereinusa

Everything that is on when in the acc position should be on when switch is in the ign position.

Well... yes. I agree; that's how it is today. The question is when in the spring-ignition position, should ACC be on as well as IGN, as it is in the 2 o'clock position (which it currently is not).

[somewhereinusa]

It's been a long time since I tested an ign switch. If I recall when in the start position starter runs and ign terminal is hot acc terminal is not. When in run position ign terminal is hot and acc terminal is not. The acc position is, basically, so that you can listen to the radio and, maybe some lights, without having the ignition coil/points on. I don't think it makes much difference on a diesel.
I always change my radio to always hot so I don't have to mess with the key to turn it on.