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How to access starter to measure current draw? (A0C1 CAS Output, terminal 50 )

7K views 36 replies 5 participants last post by  SunglassesGuy 
Place the current meter on the battery Negative terminal or around the GRAV lead by the right engine mount arm.

Clean all B+ battery terminal points from the battery to the engine compartment jumping point>to the front capped nut junction>to the rear capped nut(positive wire is inside the main wiring loom plastic protective housing)>to the starter B+ feed thick red wire, theses point are HOT all the time, and should have strong connection for strong battery voltage and current to flow and kick the starter motor connection. The final starter B+ positive connection must be cleaned and tightened.

For Ground, make sure the battery Negative cable is cleaned and tightened. GRAV lead is not loose, damaged burned, or corroded.

Use Scotchbrite or fine sand paper to clean the connections.

Once you test the starter B+ final connection and it has battery power not less much from measuring at the battery direct positive terminal, next test battery at the braided wire on the body of the starter with start up button pressed (solenoid click) you should also see battery charge, if you have both battery power on these two points replace starter.
 
CAS activate the the starter circuit, the starter relay is built inside CAS, if you hear the starter solenoid clicks means the starter KL50 circuit is activated and you will find 12V power is sent to the starter solenoid, gain access to the starter solenoid you will find a plug connected to the solenoid. Next stage is connecting the B+ to the starter motor to turn it as I mentioned in my previous post, test the 12V points where the starter motor should turn, when 12V verified and the the starter motor stuck hit it with a mallet and try to start.
 
I would believe if there is high resistance in the starter line the solenoid will be limited and will not activate and clicks and possible also the starter relay will be burnt inside CAS. But for this case it seems the issue is in the starter itself not connecting B+ or B+ power to starter.
 
Don't jump items in red, you don't need, that signal is available at the starter signal line plug that's connected to front of the starter (solenoid), by the way, if you pulled that connector you isolate CAS.

Don't complicate things, I know we all hate to remove intake plenums but for this you need to to troubleshoot the starter easily and safely. You only need to measure 12V at the B+ with ignition off and the braided wire with start button pressed, if both are having 12V it is the starter, either whack it or replace.

Forget about the DME terminal KL50 signal, it is only a reference signal.
 
Still waiting on removing the plenums and measuring the B+ wires on the starter itself as mentioned before.

Anyhow, mmm back to your waste time method "kidding", repeat the test above, in the second picture choose YES, let see how the result outcomes.
 
Check the braided wire to see how the starter internal circuit function. Seems the starter is internally shorted or stuck, have you tried to whack it?. Or a weak battery, have you tried different battery or jump it with another car?.
If the 12V B+ voltage drop when you initiate starting, try to remove that cable from the starter path and see if the voltage drops. You can isolate the starter by removing the 17mm plastic nut either the forward or the rear ones to check the voltage drop, just cover the B+ cable terminal when you remove and not to touch the chassis or it will spark.
 
In the engine bay picture at front of the engine main wiring loom plastic cover the front connectors are removed, Did you just removed them?. Is there any other wirings removed?.
Wonder if turning the engine might help as well?
Not sure if it will help stuck the starter, for the starter to turn with transmission in gear the "plunger" must be extended as you mentioned earlier
OR
Prepare to turn crankshaft with 32mm socket at front, extend the plunger and crank the engine with a ratchet or a long bar to see if it is stuck (to do this safely you need to disconnect the battery B+ cable form the starter path by removing the 17mm nut, isolate the cable going to the starter, or the engine will turn and might start when the starter got unstuck).
It looks to me that the 12V B+ on starter travels directly from starter to the jump location (left side shock tower). If I remove one of the 17mm plastic nuts, it will remove power from 12V B+ at starter. Did I overlook something?
I already explained this in post#.3. The battery/charging cable comes all the way from the battery to the jump point and then spliced to the front 17mm nut and spliced to the starter and to the alternator.
 
I think you can extend the plunger with just applying 12V to the starter connector (I think) without pressing the start button to rotate the crankshaft, still remove the B+ cable from the starter path.
 
It is not uncommon for that connection to get loose, I am sure this case is the second one , that was the next to check but you were late on measuring the braided wire which will confirm the current isn't flowing and that take the starter from the equation temporary since it is not supplied with B+ enough juice under load demand, just like weak or dead battery, but you confirmed battery is not the issue.
And why does voltage not drop to zero at other points along that same circuit?
The solenoid isolates the high current from attacking the startup circuit.
 
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