crazy instrument cluster

model 2000-es -code-p1687,says pcm is not recieving message from instrument cluster mudule and no mic bus message. after disconnecting the battery and or installing a different instument cluster everything works perfect for about two days then all syptoms return-no speedometer ,tachometer,or temperture guage and sometimes the idiot lights come on.print out at auto zone also said possible bad electrical connection.please help thanks.

I dont know about the 2000's, but on the 1stgen Neons, it was fairly common for the instrument cluster to have goofy problems. The cure was to remove the cluster, take the circuit board off the cluster and turn it over - so you could see the solder pads were the connector pins were attached to the circuit board. Then you would carefully re-solder those pins to the pads. If you looked with a good magnifying glass, you could see cracks in the solder joints. I did this to our family's Neon, and to the Neons of some family friends. There used to be a good 'how to' on this on another Neon forum, but I cant recall what the link was.
I always used a tiny bit of new solder, just to have the new flux and solder to 'improve' the factory joint.

i think from here i need to use the electrical wiring diagram + disconnect the battery and ohm it out from the back side of cluster (harness) to the (pcm) harness -diagram shows two or three splices ,one goes to data link terminal-also this cluster + circuit board is different from the first gerneration.also thought splicing new conductor from just behind plugs at pcm and cluster or installing a switch from around fuse box to kill power to pcm everynight ,since after disconnecting battery everything works fine for approximetly 48 hours..just have to turn the switch off ,when done for the day + turn it back on before starting it back up.