Yeah it was weird when I had the no crank no start issue over a month ago and replaced alternator and belt then it started up and was able to crank and start , then within a couple weeks it went back to no crank no start again! I will perform the other test you sent me tomorrow and see what I get!

 

At this point the goal is to change from "no crank" to "crank", whether or not it starts. The alternator doesn't need to be present to crank you know that. One is starting circuit the other is charging circuit.
The relay is also pretty straight forward, 85 gets ground (less than 5ohm resistance), 86 gets 12v, relay energizes then 30 (current battery voltage) connects to 87. When you get 0V at 87 (WH/PK wire) that means the relay is not energizing. You are to test just the WH/PK wire at the relay for non-zero volt, technically your starter doesn't need to be present.
Below diagram locate G104, don't get mixed up with G101 (on the upper right), that's the ground point for the BK wire (terminal 85). If you get high resistance after the test tomorrow you may need to clean or replace the BK wire or terminal at G104. If you have electrical contact cleaner, use it, if not, isopropyl alcohol 90% or higher works as well, if you don't have it too, grab one at Walmart it's cheap.
The pinpoint C attached previously that's just for your reference, you don't need to go over that.

 

Heiko, thanks for the info.
What we really need here is a POWER DISTRIBUTION diagram showing power path and grounds. .Can you do this ? If so , thanks.



A little footnote, the starting system aside from power available, has nothing to do with communication problem involving scan tool.
Tunnel vision can put us on a wild goose chase.. If we work together we can help this gent get out of this problem.

 

Ok I bench test the new and old relay and both getting conuity between pin 85 and 86 and it did make a clicking sound when I energized of battery
I am also getting 12 + voltage to all the sensors, TPS , MAF, coil box and others
getting 1.5 ohms at G104

 

1.5ohm at G104 is good at the ground point, but what about the BK wire at terminal 85? This has to be under 5ohm as well otherwise you have to replace this entire BK cable.

Terminal 85 and 86 to energize the relay, terminal 30 then connects to terminal 87.
When you do the bench test and it clicks that's a good sign, but you have to make sure terminal 87 is getting the same voltage as terminal 30 when the relay is energized. Because previously you said 0 volt at terminal 87 at the relay.

If you get voltage at terminal 87 on the bench test, then plug the relay back in and test again, I don't see why you get 0 volt again, perhaps you didn't test correctly previously.

 

As you know, a circuit with poor connections can provide a high/normal reading, but when loaded because of the poor connection can provide anything from 0 to near correct reading... Those darn electrons lol.

An example, If there is a poor connection at the cable connected to the positive post of the battery, you will read 12 volts or more. But when you go to start the engine you might a click or nothing.and yet the reading showed 12 volts. That is why we need to check some readings with the circuit loaded, like attempting to start the engine when checking the starter circuit..

 

At this stage, the goal is to get voltage up to terminal 87 at the relay, doesn't matter if the starter motor is still on the car or already removed, also doesn't matter it's 12.5V or 12V or 11V or 9V, as long as it's non-zero Volt.
If you read the entire thread again, you will see he already tested the TN/RD wire at terminal 86 of the relay with 12.38V. This TN/RD wire is the trigger wire from ignition switch thru the range sensor to terminal 86.
Terminal 85 is the BK wire and it connects to G104 ground point, not PATS.
Terminal 30 is always hot at current battery voltage and he received 12.56V previously. Even if his battery is dying and at low SOC with 9V, terminal 87 should get the same 9V when the relay is energized.
To make sure the relay can energize make sure the BK wire (terminal 85) of the relay is not bad (5ohm or higher is bad). This is the current status as of this moment, nothing to do with the starter motor.

 

There is an easier way to verify some of this circuit.
With a jumper wire from battery positive post , insert the wire into the relay white/pink wire slot (relay terminal 87) and starter should operate . Does it ,yes/no.
If the starter operates there is a problem from the relay back to ign sw..
If it does not operate, there is a problem after the relay and that is the small wire going down to the starter solenoid on the starter.
Let us know what you found and we can go from there.

I suggest the above because,
If there is only ONE strand of wire, at wire terminal, you will read 12 volts and there is not enough current for anything to operate except the voltmeter

 

Ok getting 0 ohms at 85
Getting 12.56 V at 87
Starter does turn over with jumper wire to 87

 

You said 12.56 V if you jump directly from battery positive post to terminal 87, does that mean you are still getting 0V at terminal 87 without the jumper wire when you turn the key to START?
If you are still getting 0V that means the relay is still not energizing.
0 ohm at terminal 85, how about terminal 86 the TN/RD wire, you said you got 12.38V while cranking previously.