I spent the last 2 days removing the dash by the Hanes manual and swapped the heater core and then reassembled in reverse order. It took me right around 12 hours of labor to do. I very diligently made sure all connections were made and now the car will only crank and not actually start.

I had somewhere to be right around the time I finished (ended up riding my bicycle) so had no time to really troubleshoot but I did check all the drivers side fuses which were all fine and I next intend to check engine compartment fuses and verify all connectors are seated completely.

Any ideas would be greatly appreciated.

 

How about some ground wires left disconnected?? Either under the dash or out on the thermostat housing??

 

1. When you turn the ignition to ON, does the Check Engine Light come on for a few seconds and then go out, or does it not even come on?
2. When you turn the ignition to ON, does the Immobilizer System Indicator come on for a few seconds and then go out, or does it start to blink?

Although you stated you diligently checked all connections, if you unplugged connectors at the fuse boxes, ECM/PCM, etc., that is a lot of connectors on the dash harness; in addition to the engine harness coming into the cabin for the ECM/PCM. The ECM/PCM's ground is located on the intake manifold for your car; although, you probably did not remove that, take a look anyways at the condition of the ground wires and connection there.

 

I took your suggestions and verified the indicator lights and grounds. Found everything in working order and then I verified all fuses and relays. I should have just poked my head under the dash. When I looked there was a brown connector attached to the drivers side fuse box that had not been seated all the way. It had two 12 to 10 gauge wires on it. Thanks for all the help. Attention to detail was the culprit.

 

So, everything is okay now? If so, glad to hear it.

 

Yes, all is well, I have a few other pre-existing things like error codes indicating bad O2 downstream sensor but I'm too pooped to look into that at the moment. I am a novice so to find out I successfully attempted the daunting task of changing the heater core after a minor hiccup is very rewarding. I used a calibrated kitchen meat thermometer and had the heat full blast get up to 150 degrees. Thanks again!

 

There's so much stuff under there, it's easy to pull on a wire without realizing it. Glad it's OK.