Grand Caravan LE AWD engine problems

Hi all,

Im having some odd problems with the 3.3L engine in my Grand Caravan LE
AWD.

A problem showed up yesterday where the engine temp gauge was going
from mid point (normal) to very hot every few mins randomly.
I had a breif chat with a mechanic who sugested the first thing to
check/replace would be the thermostat.

So today, i got to work removing the igniton coil/ignitor from the
intake manifold to access the thermostat housing, and then changed over
the thermostat.
I then put everything back together.

Now the engine wont start... well it has a couple of times, and then
idles fine, but when trying to rev the engine, it runs very roughly,
then stalls.

Im 99% sure i have the ignition leads back on in the correct order (if
i didnt, it wouldnt idle anyway), and i have checked the other
electrics connectors around the theromstat that i could have
bumped/moved.

So now im looking for other electrical issues. I have checked battery
connections, the ECU connector, most of the sensor connections.
I have not been able to find the cam & crankshaft sensors though.

So does anyone have any ideas for things i can try?
Can anyone describe to me where i can find the cam/crank sensors and
plugs?

I have also tried to check the engine error codes, but the off,
on-off,on-off,on-off,on trick does not seem to be working at all.

Thanks for any help!