My 1992 Plymouth Voyager check engine light has been on for4 days and just today the check gages light turned?

The motor of my Plymouth Voyager 1992 was exchanged to a motor of a Plymouth Voyager 1997.That was 2 weeks ago,about 4 days ago the check engine light turned on I took it to autozone to be checked with a diagnostic and the code it gave was 55,the man from autozone told me it could be the charging system or no distributor detected.I've been having a little bit of trouble every time i turn on my car.Today I used my car and drove for about5 miles and suddenly the check gages light came on and a battery light too.I noticed that my vans temperature was cold after the check gages light came on the temperature was normal.I turned of my car and tried to turn it on again it didn't want to start at the first try.Can you please help me ? Thank You.