Ok. A few years ago we had the engine replaced in our 1996 Chrysler Town & Country LXi with a used one with less miles on it after the original engine was found to be knocking. After engine replacement, the reverse lights would not go off and when you turned on the front windshield wipers the transmission would lock in gear (1st I believe). We had the engine installed at a garage. Only after removing the wiper relay or fuse (I forget which), everything would return to normal until the wipers were turned on again. Also while the trans was doing that the wipers would not turn off when the switch was used. Here is a conversation I had with a "JustAnswer" mechanic back in '08: I have a 1996 Chrysler Town & Country Minivan that I recently - JustAnswer

We spent alot of money ($1,500) and never got any enjoyment or use from that van after the install. It was like we flushed our money down the toilet. The garage wanted nothing more to do with it, and we brought it to two other mechanics (as well as the JustAnswer mechanic) and they could not find the answer either.

Fast forward to today.....the van has been sitting since then and has developed other problems from sitting. We didn't know what else to do with it. Now the wipers don't work at all and the trans won't shift to a higher gear. Also the right turn signal indicator doesn't work (but the turn signal outside works) and the speedometer doesn't work. The van hasn't been used since '08 and the trans worked fine before the install and the reverse lights had no problems either. I know what you're thinking....how did the mechanic who installed the engine not notice the reverse lights were stuck on and let the van leave the shop?? HE REMOVED THE BULBS SO WE WOULDN'T NOTICE!!!! The second mechanic we brought it to noticed the bulbs were removed.

Now we stand to lose a sh**load of money because now this is worth practically nothing. It starts and runs and drives but with the shifting issue as mentioned above.

Anyone have any comments as to what the hell we do now and if an issue like this can be fixed or is worth being fixed?

 

While reading through the forums, I ran across a post that discussed turning the ignition key to "run" and then back one notch 3 times to get an error/diagnostic code. I tried it and got the "Service Engine Soon" icon to blink 3 times, then 5 times, then 5 times again, and then it stops. I recorded a video below. You will see 3 icons flashing all at once, thats me turning the key off and on. After that look at the center icon and watch it blink the 3-5-5. Sorry for the video quality.

ERROR CODE VIDEO

 

Watch it again. It's not blinking 3. It's blinking 1 then 2 giving you a code 12. Luckily just about every van out there will blink a code 12 at some time or other. Just means the battery was disconnected in the last 50 start cycles.

All MIL codes have two digits. A code 3 doesn't exist.

You'll have to get a meter and wiring diagrams out and trace down the problems. May be a compatability mismatch in a connector somewhere. Hope you filed a BBB report on the boneheads that changed the engine. Did you consider small claims court?