Hello.
Mt dad's car (the model in the topic) will not start.
This has happened multiple times;
It stops working, gets sent to be repaired, comes back working, then stops again.

My dad told me to find a blueprint of its circuit system, because he said that there may be something wrong with the computer, and the repairmen refuse to look into that possibility.
I have searched for it unsuccessfully, and I'm here to ask if anyone would be able to give me a diagram of the car's computer/circuit system.
Thank you, and I appreciate the help.

 

You won't find a single diagram of the computer circuit. The complete engine performance diagram of all the senors and computer is about 10 full pages. Instead of scrambling around for freebies that probably won't match your vehicle (since you didn't tell us which engine you have and each is a little different), buy a 1-week subscription to eautorepair.net ($13) and print out all the diagrams you want. They will be specific to your vehicle and engine and far more reliable than anything you can find for free online.

The other big advantage to that subscription is that the Engine Performance section contains a complete description on the Theory and Operation of each sensor in the system. And, the component locator tells you where each one is located.

You'll also need the trouble codes to start your diagnostics. Without those, you're just shooting in the dark.

Once you have reliable diagrams and trouble codes, you can get to the root of the problem.

 

We experienced this on our 97 grand caravan as well. We used to have to hit the relays with the plastic cover that protects them and the vehicle would start. Thinking it was a bad relay we replaced them all, same problem. Turned out to be the distribution box the relays and fuses plug into. Speculation at the time was that Chrysler had a problem with the anti corrosion grease they were using in their Mexico factory that these boxes were made. I disassembled the defective box and it was heavily corroded at the connection joints of the wire back plane. Note: You cannot successfully put the box back together, it is toast, chuck it. The replacement box solved the problem for us.

 

I have a 1997 dodge caravan we rplaced the battery but now it will not start last night I put it in neutral to get it to start does this usually meen the starter relay may need replace?

 

It's nearly always best to start a new thread instead of jumping on an old one. You'll get more eyes looking at it. You're here so:

If it starts in neutral but not park it points to the transmission range sensor in the 41TE 4 speed transmission or the park/neutral safety switch on the 31TH 3 speed transmission.