Hello,

I recently purchased a 2007 Chevrolet Equinox for a very reasonable price, considering that the vehicle is suffering from an issue and will not start. Allow me to briefly describe what is happening. The seller informed me that after performing an engine swap, the vehicle ran fine until the engine wiring harness was replaced.

So, despite a full charged battery the vehicle will not crank when the key is turned to the start position. When the key is in the on position, everything lights up normally, the gauges sweep, etc. When turned to the start position, everything goes dead until the key is released.

So obviously, thoughts like a bad ground, failure in communication between modules, incorrectly seated plug along the wiring harness have come to mind as possible culprits.

When inspecting the old wiring harness which was removed I noted something odd. A set of wires had been spliced into the tan and tan/black wire from the TCM connector, running to the plug which connects to the bottom of the fuse block.

From what I understand, those wires have something to do with the CAN network, and I'm guessing those wires spliced in are some sort of backwoods work around.

I am looking for suggestions as to where I should begin.

I do not yet possess a bi-directional scan tool, but will be purchasing one in the coming weeks to help assist in further diagnosis.

Any thoughts or suggestions would be greatly appreciated.

Thanks you!

 

Have you confirmed the starter is still working and that the starter solenoid's ignition (S) terminal is receiving power when the key is turned to the START position? If not, I would start troubleshooting there before messing with those TCM wires. It's normal for the instrument panel to go dead when the key is in the START position, but everything should come back on when the key is released and returns to the RUN position.

The starter won't operate if the starter solenoid isn't getting 12 volts at the S terminal so I would first determine whether or not this is occurring and go from there. If it is, you have a bad power connection or the starter is bad. If it's not, you'll need to troubleshoot further to figure out why.

 

Update**

Well after charging the battery, and reviewing the wiring schematics on all data, I decided to do a little digging around, simply checking all of the fuses, wiring harness connectors, etc..
after working my way from one side of the engine compartment to the other, I decided to remove and inspect the fuse block for bent/broken pins. Upon removal I noted that one of the wiring harness plugs fell away rather easily. The plug itself was broken from it's mount surface and was in the recessed/locked position while the other two were in the raised, unlocked position.

So naturally, I adjusted the other plug so it was in the raised, unlocked position like the other two, reinstalled the fuse block and low and behold - the vehicle cranked and started.

Problem solved!

I was quite pleased that it ran, and runs very well considering how long it's been sitting. Thanks for the suggestion as it got me away from thinking a faulty module was to blame, and got me focused on just checking the basics!​​​