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No crank - no power to starter relay

9.8K views 5 replies 3 participants last post by  GroundLoop  
#1 ·
Have a no crank condition on my wife's 2006 6. Traced it down to the starter relay. If you jump the two pins (30 & 87 on the relay) in the red circles in the attached pic the car cranks. I am getting nothing on the yellow and green pins (85 & 86 on the relay). Can anyone tell me where these two pins connect to? I am thinking one is the alarm immobilizer. The red icon on the immobilizer on the dash is flashing normally. From my research the immobilizer put a ground to the pin if everything is OK. Thinking the other pin connects to the ignition switch and puts out 12v? Thanks for any help in advance.
 

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#6 ·
Thanks guys. Fixed it this morning. I always pull the fuel pump fuse when doing engine work. No sense in constantly energizing the fuel pump washing down the cylinder walls. Unfortunately the fuse labeled "fuel pump" does more than just the fuel pump. It also provides the control voltage for the starter relay and something related to the immobilizer because the immobilizer light was flashing when in gear with the fuse pulled. When the fuse was put back in the immobilizer light then acted normal. So that answered one of the control pins on the relay. The other pin than has to be a ground coming from the ECM. Turns out the park neutral switch must be on its last legs because once I put the fuse and relay back for the starter the car would not start in park but it would start in neutral. Ran through the gears and few times with a little more force when putting it back in park and now it starts in park. Will likely change the park neutral switch.
 
#4 ·
Replace your fuel pump fuse with a brand new SHINY one. Don't use the unused one in the lid. Its probably corroded too much to pass full current through just like the one already installed.
I ended up replacing all of my under hood mini fuses for $8 it was worth it.
 
#3 ·
More info. Did not notice the immobilizer light flashes even with the ignition on. Hooked up my simple bluetooth scanner and it gives code U0100 with no other info available. Searched u0100 and found a large amount of possibilities. Everything else seems to work including the fuel pump running when the ignition is first turned on.

No difference with the spare key which has rarely been used. So I do not think it is the key.
 
#2 ·
Gained access to the ignition switch and the black with blue stripe wire has power when in crank mode. Thinking maybe the neutral safety switch is in between the starter wire and the relay. Tried putting the car in neutral and starting - still no crank. Cannot find a schematic for the starting circuit.
 

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