Automotive Air Conditioning Information Forum

I just bought a new clutch kit for an older vehicle. The original service manual indicates a Zener diode between the coil leads to deal with voltage back flow. I haven't pulled my original coil yet but I find no visible diode on my new coil. Could the diode be out of sight under the wrapping with the coil windings (I feel no "lump") or elsewhere in the wiring harness? Or should I add my own if not sure?
Thanks in advance.

I have seen diodes mounted on the connecting plug of the harness.

thanks but It's not at the connector.