Use of ので
I know the te-form can be used to imply causation, e.g.
(My head hurts because I have a cold.)
But would it be wrong to insert a ので? Like this:
Your sentence should read
Both て or ので can be used in such sentence, with different implications.
て is a connecting particle. It connects two subjective facts (I have a cold && My head hurts). The causation is implied, as if the 2 facts naturally happen one after the other.
ので is also listing 2 facts, the 1st fact being a context, the 2nd fact being a natural outcome in the speaker's belief.
Test your sentences by translating て by And Then, and ので by Given The Fact That.
I have a cold and then my head hurts (OK)
Given the fact that I have a cold, my head hurts (OK)
I have a cold and then please give me medicine (a bit weird, right?)
Given the fact that I have a cold, please give me medicine (OK)