Grand Caravan 1998 not starting

Hi!
I have a 1998 Grand Caravan 3.8L engine with 157K on it. A month ago changed the EGR valve and replaced the transmission oil. Two days ago, went for shopping, parked the van. Came back and did not start (no crank, nothing). Called AAA, checked for battery, which was good. Radio, wiper, lights work. Had to tow to the shop. The mechanic checked for all possible problems. Said everything (Fuse, battery, starter motor, alternator) is good. He is clueless. Told him to check the ignition switch (may be worn out). He says it doesn’t seem so. Can anyone please help. Thank you.

There’s a starter relay in the fuse box under the hood. If that hasn’t been checked out that might be the problem.

Tester

Hot jump the starter with a jumper cable from the pos of the battery to the pos of the starter motor stud, if that works it may be a bad cable or connection, find a new mechanic.If that does not work clean and check ground connections and cable.

The engine/transmission wiring harness is attached to the front of the transmission oil pan. If this harness is left loose after a transmission service the harness will droop down and may get caught on a park stop, curb or sidewall. The wiring harness may be damaged, if your van has the 3.0L/3 speed the neutral safty switch will become unplugged.

Checking the neutral safty switch/range sensor and starter relay are basic tests, if your mechanic hasn’t done this it is time to find someone else.

Thanks for the suggestions. I will talk to my mechanic first thing tomorrow and see what he comes up with.
@ Nevada_545: My van is a 3.8L/4 speed. Do you still think that they same is possible ?

It is possible to damage the wiring harness. It is easy to test the starter relay inputs and output. Something to be aware of with double-start override is the PCM monitors the range sensor (gear shift lever position) and provides the relay ground to start if in park or neutral.

Spoke to my mechanic. He has checked for hot jump start, it works. So no probs with the cable or starter. He checked for grounding, transmission wiring harness. They are yet to start working on my car today. He says, it could be the PCM. However, he wants to make sure nothing is left behind. He has checked for the relay switch too. If the PCM is bad what could be the reason for it to go bad?

A defective PCM won’t prevent the engine from cranking over. The PCM doesn’t come into play until the engine starts.

Tester

The double start over ride feature uses the PCM to control the starter relay so that you can’t engage the starter if the engine is running.

Connect a scan tool, if the PCM is dead this would explain why the starter doesn’t work.
Next question, why is the PCM dead? Has it just failed or is there no power to the PCM?
If the PCM is alive is the PRNDL input correct?

What else could be the reason ?

My mechanic is still figuring out the problem, in the mean time when I called, he said that the fuel pump does not kick when he hot jumped the starter. Why would PRNDL input go wrong when the van was running all these days and nothing was changed? Is there are reason for this to go wrong?

@Villa: I hate to be the one to say it, but troubleshooting a no-start condition shouldn’t take a competent mechanic days to do. If the engine isn’t cranking, it’s pretty basic to check power at all components in the chain. A starter relay can be jumped or temporarily swapped with a similar non-critical relay (like the A/C relay if it matches) to check if it’s the problem. The neutral safety switch can be bypassed for testing. If the ECM has its hand in the process at all, voltage can be checked for at the appropriate cavity in its connector. He said “the fuel pump didn’t kick in when he hot jumped the starter” Why would it? Applying power directly to the starter has nothing to do with the fuel pump. The fuel pump should run for a few seconds when you turn the ignition on, then shut off until the engine is cranked with the ignition key. If the fuel pump doesn’t run briefly when the ignition is turned to the ‘run’ position, you may have a bad ignition switch, a blown fuse, a wiring issue somewhere, a bad ECM, or a problem that may be entirely separate from the no-cranking issue and just decided to rear its ugly head coincidentally at the same time.

To answer your question about why would something go wrong when the van was running all these days and nothing was changed—that’s life. Things work until suddenly they don’t any more. It’s a natural process of decay, and to be expected with any 15 year old vehicle.

Thank you for the details. The shop was short of people and hence they took time. Finally, the van started on its own. The mechanic checked for codes, did not read any. He checked the voltage by connecting to the battery and the PCM, when the car was turned on. The voltage kept jumping all around from 0.89 to 12.69, never did it show one number for even a full one second. Then, he also showed me that even after pulling the fuse responsible to the PCM was pulled off, the engine was ON. He said that it is taking current from somewhere and asked me if its okay to go and find it?. Since, he said it is labor intensive and really does not know whether the harness is bad or something else is bad, I just asked him to put it back. I will drive it home. Any thoughts or suggestions?

The fuse he pulled out may have been for the PCM memory instead of the operation. It sounds like the tech isn’t real savy in fixing electrical problems and I think you were wise in taking the car back.

It is hard to say what was causing the erratic voltage reading. If he was on a point that should have constant power then there is a bad connection somewhere but appartently that issue didn’t keep the engine from running. Using a wiring diagram a tech with good electrical skills should be to pin down the trouble without much time spent on locating it. It appears the trouble is intermittent so that can be a problem in finding the trouble. You may want to try to find a shop that specializes in electrical problems.

@Villa: It sounds like he’s making some progress, but it also sounds like he doesn’t have much of an understanding of how the system operates or is trying to snow you. If the car was running, the voltage should have been way more than 12.69 at the battery. Plus, if he was just holding the meter on the battery terminals, this can make a poor connection and cause the meter to jump all over. Depending on where he was measuring voltage to the “engine”, there could be multiple back feeds from systems, and I have no idea what he was trying to do investigating a no-start issue by looking for where power is coming from that is actually present and not missing.

Anyway, good luck with the issue and please post back when the cause is found.

Thank you for the post. I will try with someone with better electrical knowledge. Will post once I get to know the cause. Note: The mechanic did say that when the terminals were connected it should read 14 volts, he plugged the terminals and was not holding by his hand. I am not sure about the fuse. Believed in what he said to me.

Tried to drive my car to a shop who can deal with the electrical problem. Pulled the car is reverse from my parking lot, and was about to move on ‘drive’. In between comes the ‘N’ and my car just turned off even before reaching the ‘D’. mmmmmmmmmm…is this a neutral lockout switch problem? I tried to start my car in neutral and in parking position no luck. Pushed the car back to parking spot…wondering what to do next? Can anyone suggest some simple test/techniques to be performed? I have already spent considerable money with the shop for them to ‘Find’ me the previously mentioned issues (June 3 posting). Now…what? Can even drive this to trade it in?

@Villa: No, the neutral safety switch will not make your car stall. It is only used to prevent starting in any gear but neutral or park. It could be the same electrical problem that is causing the ‘no crank’ condition that caused the stalling, but it sounds like you may have a separate problem. If the van won’t start and run, obviously you won’t be able to drive it to trade it in.

I’d bite the bullet and have it towed to a shop that can properly diagnose it. The vehicle will not be worth squat to trade in with the existing problems, and it sounds like although it’s sick, it’s still worth fixing. Electrical problems can be a pain to diagnose, but certainly aren’t as bad as a failing transmission or engine, for example. Depending on the amount you’ve spent with the first shop and what was actually wrong with it after it’s properly repaired, it might be worth trying to recoup the money spent with the first shop.

@oblivion is right: the car is practically worthless if you “trade it in”. Even if you sell it, you’ll be money ahead -far ahead- by selling a running vehicle. … that is unless it otherwise worn out, body and interior bad plus burning oil, needing other expensive repairs.

Tow it to a good auto electric specialist shop. You already posted that you used AAA, so just use your towing benefit to tow it to the right shop. Of course do some homework by checking out the best shops in advance by using another vehicle to go to each one to determine which is most experienced.

If your car is otherwise in good condition, the smart choice is to get it fixed. It could well be something simple and relatively inexpensive to fix, once the problem is diagnosed accurately.

Everything works until it breaks. On an old vehicle this is especially obvious. After so many years and so many miles many things start to wear out or break. As a driver of old vehicles myself I have experienced many times where my vehicle ran great and then one day, for no particular reason, it did not. No amount of maintenance and gentle driving prevents old age and wear from slowly breaking down components until one day something just breaks. All you can hope for is that it happens near your house and that you have (or you are) a very good mechanic.