Electrical Relay Question

[wmburns]

Take a look at the attached diagram of the power flow in the Mustang. It helps to visualize how the pieces are wired together.

Assuming the tests have been REPEATED with the car in it's current repair with the results claimed then I will make good on my offer.

Since there are still things to learn I would be interested in hearing your explanation WHY the tests get the results posted.

 

[Clinton King]

I'm not concerned with whether you believe me or not and I'm not looking to get anything from you. If I knew how everything worked I wouldn't be on here but I do know from experience that there are no certainties when it comes to electrical! Electrical problems can be caused by many different things and to act differently than you think it would. You can have one common problem on 10 different vehicles and have 10 different cause for that same problem. I'm done with this thread. Thank you for your help

 

[wmburns]

Final thought. I may have an idea WHY there is confusion here. It is HOW the test for power was done. I'm suspecting that the leads of the VOM were placed across the COP under test instead of testing between the COP and a known good ground.

Why does this matter?

Because the ground is being provided by the signal return wire via the PCM. In the case of a bad or missing PCM the signal return is open. That means that there could indeed be power at the COP but without a ground to reference by, the VOM meter will read zero. A false negative.

Unfortunately I assumed the testing method. In the future I will try to be more specific in how the tests should be done to give good results.

To prove no hard feelings if you send your US mailing address via PM, I will send you a copy of the wiring diagrams.