Hi everyone. Allow me to add a few comments of value that might get you looking in a different direction. This is based on the symptoms listed in the original post.
The place I would start looking is for broken solder connections on the connector on the back of the instrument cluster. This is a real common problem. I only repaired one van for this and that was a number of years ago, so I'm doing this from memory. The huge clue was that pounding on the dash pad would change the symptoms. As I recall, the engine would not even crank, but if it did, it wouldn't start and run at times. The anti-theft light did something abnormal too, but it wasn't actually in theft mode. When it is, the engine will start and run for two seconds, then stall for lack of fuel. I don't remember hearing that it would stall intermittently while driving, but the symptoms will vary from one van to another depending on which terminals are broken loose.
There are two rows of connector terminals. The one I repaired was in one of the corners. Looking at this connector view, they show two corner terminals are ground circuits. Those will affect multiple circuits or systems.
For the failure to crank after three tries, that is designed into the software and there's nothing to fix for that. Just wait a minute or two. This was frustrating at the dealership, but the engineers' thought was the engine should be running by that time and they lock out the starter system to prevent trying to crank the engine while it's already running. My reply was they found a solution where there was no problem.
My suspicion is the ignition switch is not a good suspect unless testing proves otherwise. It actually has three or four separate switches built into it. The part for cranking the engine sees very little use, and when it is turned to "crank", it passes very little current to run a relay. By far most failures will involve the part that turns the accessory circuits on and off. That includes power windows, the heater fan, and radio. This problem was much more common on slightly older models that used a different switch design, and my suspicion is it affected mostly people who were in the habit of turning the ignition switch on and off while the heater fan was set to a higher speed. That forced that very high current to be switched on and off by the ignition switch, and that led to excessive arcing across the contacts in that part of the switch. That led to heat buildup that eventually migrated out to the connector terminals, to the point the plastic connector body would melt around those two terminals. Remember, that failure only affected those accessory circuits. The engine would still crank just fine and run normally. When you run into any high-current switch or relay with overheated terminals like that, the only acceptable repair is to replace that switch, the two terminals, and about four inches of wire for those two terminals at the same time. If only the switch or only the terminals are replaced, the problem will occur again very soon. I can describe that repair in more detail if that becomes necessary.
I never ran into this ignition switch problem on the redesigned '96 and newer Caravans. Most of the high-current circuits are switched off and on by multiple computer modules now instead of simple, inexpensive switches, so that takes the stress away from those ignition switch contacts.
Image (Click to make bigger)
Sunday, February 19th, 2023 AT 5:02 PM
