Head Unit Install into Harmon Kardon

[mtelliott]

A lot of information out there but none that specifically address what I'm looking for. I have a 97 M3 with the H-K system. Not looking at replacing the system for now but am looking for updating the head unit.

Head unit I'm interested in has the RCA pre-outs. My specific questions is: did the stock head unit have amplified outputs or line level. Trying to figure out which wiring adapter I should purchase for install.

There are two wiring harnesses options:
1) One is just normal wires block that plugs into the factory harness and wires up to the harness out of the aftermarket head unit. This is the unit Wayne showes in the 101 projects.
2) The other incorporates RCA level pre-outs that plug into the factory harness.

My instinct is to use option #2 however if the stock head unit actually uses amplified output and sends that to the stock amp which is able to accommodate, then using option #2 will be the wrong solution since the power will be significant lower.

Any one able to chime in on this?

Michael