Chevrolet Repair Questions? Ask a Chevy Mechanic for Answers ASAP
good evening my name is ***** ***** I will assist
does the car run now????
ok, the small purple wire on the solenoid, does it have 12 volts with the key in the start position????
wiring diagram for you
how are you making out
ok, then tell me the voltage with the key on??? one terminal should have 12 volts. one other one will have voltage for only 2 seconds. you can see in the diagram I sent you.
first, check the ignition e fuse in the diagram. that is the second feed check the diagram for the what I am talking about
does the security light sty on???
does the relay energize now??? can you feel it click??? did the new fuse blow????
just got on. be back to you in a little bit
sorry, just drove 400 miles today home
ok, we have to check and see if there is voltage from the pcm to the control side of the relay. did you check to see if there was voltage for 2 seconds on the control side??
ok,looking at the diagram, I had a senior moment. the second power or control side is grounded by the pcm. when it grounds the control side it will complete the load side which goes to the purple wire at the starter.
just to be sure, did you try another relay?? I doubt it will work if you have constant power. it is going to come down to the pcm has failed by not grounding the control side. that is part of the programming in the pcm.
I figured that. it needs a pcm.
yes it will. it can cause all kinds of issues when it fails. that will be the starting point
please dont forget to rate me as it is the only way I get paid for my efforts
did you re check all voltages again???
did you have the new pcm flashed with your vin number???
that will not work. those parts from the other vehicle will not allow your car to start. they must be programmed to your vehicle only. when there is a vin mismatch, nothing will work
did you put your tumbler in his truck too???
does the security light come on?? stay on or flash???
re check your voltages at the relay.
I am going to opt out. I cannot continue here without actually seeing what you are doing. I do not ever use used parts for confirming failures. maybe someone else has better ideas and can help you better.
Ground the yellow/black wire that comes out of that starter relay and goes to the pcm pin 48 of connector 2, then turn the key to start and see if the starter cranks now.
Even before that, ch3eck the "crank" fuse #17 in the underhood fuse block.
Ok, it's either a faulty PCM or the voltage from the crank fuse isn't making it all the way to the PCM. Double-check and make sure that the crank fuse has voltage with a voltmeter or 12 volt test light on both sides on the fuse when the key is on start. Then if it does, check again at the PCM purple wire pin 31 connector 2, again key on start. If it does, then I'm afraid you have a faulty PCM most likely.
Ok, first of all. The crank fuse should only be hot when the key is on start, not run or on.
Second, I will double-check that wire at the pcm.
here is the wiring diagram I have,
It is a purple wire at pin 31 connector 1.
As you can see the wiring diagrams are not the same although they were supposed to be. Yes, C1 now.
I thought you just made a mistake typing, is the crank fuse hot with the key on just run?
Are you sure? Something isn't right, the crank fuse #17 in the fuse block underhood feeds that purple wire.
remove the fuse and check again on both sides of the fuse socket.
Just 2 posts ago you said, "The crank fuse is hot in the run position.'
Now you say, "The crank fuse does not get any power"
Which is it, one or the other?
Plus, the crank fuse should have power until the key is on START. That's START not run.
So, let me ask again. Does the crank fuse have voltage at both sides of the fuse when the key is on start?
Then you probably have a bad wire either feeding or leaving the ignition switch, since you say the ignition switch is new. That is assuming the fuse "IGN A" #34 is still ok.
Red wire going into the ignition switch, which should be hot all the time and the yellow wire leaving the ignition switch, which should be hot when the key is on start.
Then there must be an open or short in the yellow wire between the spot you just checked and the crank fuse, because that yellow wire feeds the crank fuse and you just said, "No it has no power to either side of the fuse in the start position" when I asked, "Does the crank fuse have voltage at both sides of the fuse when the key is on start?"
It could if it's actually a short circuit. Jumping won't fix the other problems but it should tell you whether or not the starter is going to crank or not. If the other problems are caused by that yellow wire being shorted out even if you do make a temporary jumper, you are still going to have to find and repair the short.
When you do jump, put an inline fuse in the jumper wire. Just incase you touch to the wrong side of that crank fuse.
Anyhow, let me know if jumping it does finally allow the starter to crank or not.
I give up, these test results keep going back and forth between testing good and then testing bad. I am going to opt out.