Car ended up dying on me after a code 16, so put a new opti on, still no start, so after reading a post about diagnosing opti off the car I plug the harness into the old opti with the body of the opti touching a ground. Then as I wiggle the harness, I realize how loose the harness is, and I hear something else under the hood clicking on, and what may have been a spark (coil wire was disconnected at the coil). Today my new opti harness comes in, and fits snug unlike the old harness, but now it won't even crank? It doesn't even click now, just turning the key to start just dims the interior lights.

What do I need to check now? I'm tired of my car not running!

 

dead battery?

 

Battery measured 11.98v across the terminals with a digital multimeter, but the dash shows lower than that and bottoms out when turning to start. Is it possible that I shorted something out accidentally? I thought that the starter would still try to crank even if the ignition system had a problem?

 

Yes, it should. Your battery does not sound all that hot and if the voltage drops too low when engaging the starter, it's not going to crank.

 

So should I just get the battery checked out or recharge it first before checking anything else out?

BTW when I tried your opti test from your site grounding each of the 4 leads on the opti connector with a digital multimeter on DC at the manifold on the PCM end (opti disconnected) I got:

A - 5.12v
B - 5.12v
C - 11.8v
D - 0.05v

Is that right?

 

I'm retarded. Well turns out the battery was just low, jumped it and it fired right up. Runs better now with the new opti and harness, pulls harder with no more high rpm break up.