I have four pins. Is there a way to ohms test it?

 

Most relays that have 4 pins on Chrysler/Dodge products are activated by a ground signal from the ECM.
Ohms should not be an issue.
Basically it either completes a circuit (continuity) or doesn't(open circuit)
Two of the connections are for the load, the other two are switched by the ECM to activate the relay and close the internal contacts which will then energize the load.
To test the relay you will need to remove it.
Using 2 jumper wires, connect one wire from the positive battery terminal to one side of the relay coil and touch the other jumper wire connected to the negative battery terminal to the other relay coil connection.
You should hear/feel the relay "clicking" on/off each time you touch the connection.
You can then test if the main load contacts are passing the current by hooking up a test light to one of the load connections and the other end to the positive battery terminal and attaching a jumper wire from the other load connector to ground.
use the previous connections you made to test the relay coil to activate the relay and watch for the test light to come on each time you energize the relay.
If those tests prove the relay is functioning correctly, then your problem lies elsewhere.
An important consideration is to make sure the relay coil is 12 volt and not 5 volts.
Might say on the relay, might not...If its a 5 volt type and you zap it with 12volts, you will fry it.
You will need a 5 volt power supply to check the coil.
A good home computer power supply should have a regulated 5 volt power supply available.
Sorry for the somewhat complicated procedure and explanation, but electrical systems are inherently so.
Best of luck and let us know how things work out.

 

How about testing the cooling fan motor relay under the head light.
Before buying a relay I wanted to check the wire going to the pcm. Do you know how to test the signal wire? I know it pulses but I don't know how to test it with a multi meter or test light. I think the pcm is working because when I unplug the coolant sensor the fans come on.

 

Sorry sir,😐
I do not know the specifics on how to perform those tests.
My best guess is that you might need a proper ECM scanner to get inside the computer's brain and see if everything is working the way it should.
Hopefully a better informed individual can chime in and direct you on the correct test procedures.
I would definitely be interested to know what the solution turns out to be.

 

I saw a video where a tech used a power probe to test the single wire (relay to the pcm). With the a/c on or engine hot the green light blinked.(pulsed) on the power probe.