Chrysler Repair: 98 minivan: anti-theft, heater/ac, insturment cluster, fuse box, grand voyager

Question
my 98 grand voyager seems to have the imobilizer cut in so not starting the engine, then sometimes it starts the cuts out. the dials sometimes are on then sometimes all drop to nothing showing,the heaters either work dont work or get stuck on super hot, do you think this is the heater control panel?

Answer
Hi James,
I don't see any common cause between these three problems other than they all have some relationship to the body control module which mediates many functions including the cluster, heater/ac panel, and security/immobilizer so that were there a faulty fuse in its power supply it might cause some of this. Check fuses 1,2,3,6 in the fuse box under the dash and fuses 19,22,28 in the engine compartment, looking for any subtle cracks in the internal wire that might cause an intermittent problem.
Otherwise, each needs to be considered independently, and I prefer to deal with one at a time.
As regards the anti-theft system, when it is alarmed it allow the engine to crank and start but then it dies in a second or so. You may have an intermittent problem with disrming the system so that it thinks you are not authorized to start the engine. It may be a failure of the key lock switch wire from the driver door to the body computer, but an alternative way to disarm is to use the passenger side door to unlock the van.
The instrument cluster when its gauges drop out may also show a message "no bus" in the odometer window. That would indicated that the digital data is not being received from the body computer to run the gauges and that is likely caused by a poor connection of the socket on the back of the cluster to the circuit board proper of the cluster. That can be remediated by removing the cluster and reheating the solder joints between the socket and the board.
The heater/ac panel needs the data wires too but first of all needs to have power from fuse 6 in the box under the dash, so that would be another reason to be sure that fuse doesn't have a subtle crack in its wire that may be opening and closing unpredictably. So you might just replace that fuse (20 amp) and be sure it is good.
Let me know about any progress when you write back, and let us focus on one problem at a time.
Roland
PS Please 'rate' my answer.