Chrysler Repair: 99 Concord (LH) radiator fans wont run, unless relay removed/inserted, radiator fans, pin sockets

Question
I have changed all relayes that pertain to the operation of the radiator fans, I have also checked the temperature sensor. The fans will not operate unless I pull the high/low relay and plug it back in while the car is running. Then the fans will turn on. My question is where else can I look, or what else could be the problem?

Answer
Hi Gary,
I will assume that when you are making the observation that the temp of the cooling system is low enough that it is the low speeds that are brought into action by pulling the high/low relay.
The most obvious cause would be a flaky connection of one of the 4 wires that supply that relay socket. So my advice would be to verify that you have power on pins A and B when the ignition is "on", and on B only even when the key is "off". A is the rear pin and B is the in-board pin.
Because it may be related to removing/inserting the relay you will want to try inserting pig-tail wires into the 4 pin sockets and then installing the relay so you can assess the voltage situation at all 4 pins without removing the relay.
The activation of the relay occurs by the PCM grounding pin C (the outboard pin) when the temp sensor reaches its threshold for low speed action, so you could observe for that response. The wire is from pin 55 of the pcm. Finally, when the relay closes you should see 12v on pin D (the front pin) and the fans should come on at low speed. I suspect you will find that either a wire is poorly connected to one of the pins of the relay socket or one pin itself is oxidized and not making reliable contact with the relay pin. Other than that it has to be something unusual about the pcm activation function on pin 55. A 'long shot' is that fuse 21 behind the dash which powers the relays coils is flaky/cracked and/or the wire from it to both relays is partially shorted to ground such that it 'opens' when both relays are in place but 'closes' when you remove the high/low. But that is hard to believe.
Please let me know what you learn.
Roland
PS Thank you for the rating and nomination.