Engine fan running 1/2 speed and relay clicking

[jrpontiac]

I am working of the relay setup for my engine fans on my LS conversion. I got a dual fan setup with each fan triggered by a relay that is activated by the engine PCM. Each fan has it's own relay. The PCM activates the fan relay by triggering the ground. My problem is that when the pcm triggers the fan (about 190degrees) that fan only runs 1/2 speed, maybe less. The relay is also clicking, both relays click. When I bypass the PCM ground with a wire clipped to a solid ground the fans click on 100% and the relays don't click.

So I assuming I have a grounding issue, my problem is I don't know how to improve the ground since it terminates somewhere in the PCM.

Any suggestions?