[Downbylaw]

Well, I replaced my heater core this last weekend since it's had a slight leak for a while, and I need heat as we get into winter. Since then, I've been unable to get the car to start. I had the heater core buttoned up, and was starting to put the interior back together, when I decided to try and start it so I can fill up the cooling system. I got the steering column back in, and the four (five, if you count the ignition switch bolted to the column) connectors underneath it hooked up, but when I go to start it, nothing. No sound like the fuel pump being primed, and the starter does not engage. There's a faint click from under the hood when the key first goes from OFF into the RUN position. When I turn the key from RUN to START, the voltage meter drops significantly, but nothing happens.

My first guess was that I simply forgot to hook something up when putting everything back together, so I double-checked every connector, and it's all snug. I used Sir William's method to get the dash out of the way enough to replace the core, so a lot of the ECU connectors never got unplugged to begin with. However, if I leave the car in RUN for a few seconds, the airbag light will blink a code 12 at me, which is low voltage to the airbag module. Voltage at the battery is 12.7. I did find one extra connector that isn't mentioned anywhere in timb's article, and I must've missed on my first tear-down. Here's a picture of it:

Asides from that, I've checked all the fuses, and the inertia switch. Still nothin'. Help?

Edit: Pulled a code P0232 (fuel pump secondary circuit high), but I believe that pops up whenever you trip the inertia switch. Just mentioning it in case it's related.

 

[Downbylaw]

More fun: Apparently, I didn't notice when it was still light outside, but if I reconnect the battery, then turn the key to anything but OFF, the headlights and parking lights come on (even though the light switch is off) and stay on until the battery is disconnected.

I pulled the entire dash again, and triple-checked every connection. I made sure each harness was in working order (no bent pins or contacts, no corrosion, etc), and the issue persists. I'm not an electrical genius, but I can follow a diagram well enough, and everything looks good according to the EVTM. This car was in 100% perfect working order prior to pulling the dash - the only problem was the slight heater core leak. Any ideas, folks?

 

[91 XR7]

I'm thinking something got pinched or broken.. i would fully pull the dash back and check all connections on both sides..

Also what was Sir W's way again??

 

[Downbylaw]

Already did, and everything looks good. I'm starting to suspect the anti-theft system for the no-prime/no-start, but it looks like a monkey did the wiring on it. It says Pursuit on the casting - no idea if it's factory or not. Since it's dark out, I'm giving up for the day.

Sir William's way is still close enough to timb's that there's not too much difference, but you wind up sliding the dash out the driver's door about 10" to gain access to the heater core door rather than take the dash totally out.

 

[Sir William]

The car won't start if you don't hook up the wiring that goes to the shifter.

 

[Downbylaw]

Actually, the shifter was never unplugged. If you're referring to the connector pictured above, that's under the steering wheel with about 2 inches of slack. There's no other matching connector under there, and I still have no clue what that thing is.

 

[master486]

That connector is for the brake-shift interlock solenoid. It's on top of the steering column near the back. But that's not going to be the cause of your problem.

 

[Downbylaw]

Got the brake-shift interlock solenoid hooked back up (thanks, master). Does anyone know if the ignition lock cylinder not sitting properly can cause or contribute to these issues? Since putting the steering wheel back in, the ignition cylinder doesn't want to turn all the way - it looks like that plastic rod that runs the length of the wheel is getting stuck on something.

 

[Downbylaw]

I've been messing with it on and off over the last few days, and I've tried:

- Using the ignition switch itself to try and start - same issue.
- Reprogramming the key fob and disarming the anti-theft. None of the power locks/windows work, and the module in the trunk won't go into programming mode when I short the two terminals.
- Cleaned the battery terminals just to be safe, no change.
- Checked the battery ground, and the two grounds on the engine mounts, looks good.

Still haven't gotten any noise from the fuel pump at all, and the starter doesn't actually crank. Just the click from the solenoid. Every other time I hook up the battery, it flashes a different airbag code. I started with 12, now I'm getting 21 and 23 as well. So, I guess my car's just possessed?

 

[master486]

I know you said you double-checked all the connections, but you must have missed something. Codes 21 and 23 are for the safing sensor, which is right by the hood release behind the driver kick panel. I don't know what steps you followed and what things you disconnected, but make 100% sure that the following connectors are securely connected.

• Large rectangular bulkhead connector that goes through firewall on driver's side, next to brake booster
• Large square connector that screws in behind the fuse box
• Two small rectangular connections (black and blue) by the PCM connector
• Two small rectangular connections (yellow/white) under the radio, connecting to the trans wiring harness

 

[Downbylaw]

Aye, there had to be something I missed. Earlier today, I was able to get the engine started. I connected what I figured to be the bare minimum; all the PCM connectors underneath the passenger kick panel, the shifter wiring, and the ignition switch (which I just replaced new). I also disconnected the airbag module in case it was shorted somewhere. With it running, I did a chemical flush of the cooling system because it's been bone-dry since I drained it initially 4 days ago when I swapped out the heater core, and I figured if there was any solid material, I don't want it getting stuck somewhere.

As I was filling it back up with a fresh water/coolant mix, it started raining pretty hard, so I'll finish reconnecting everything else and making sure it runs before I reassemble the dash tomorrow. Hopefully, I can chalk this up to a bad ignition switch or my own stupidity. I'll post tomorrow with an update. Thanks for the input, master486!