Limp mode/speedometer & odometer not working

I recently purchased a 94 Le Baron GTC convertible that is in limp mode, looks like it is stuck in 2nd gear. The speedometer doesn’t work and I recently noticed the odometer, at 127,000 when I purchased it, is now at 125, 00. I’ve driven it maybe 5 miles tops. The mechanic I brought it to didnt have an adapter to run diagnostics on an older car, so I took a gamble and replaced both the input and output speed sensors on my own. The speedometer still doesn’t work. I did notice transmission fluid on one of the sensors I took out to replace. Is that indicative of anything? I read overfilling transmission fluid can leak out the sensors, I’m not sure of what was done to the car before I purchased it though as far as that goes. I’m waiting on a code reader to come in the mail. Until then, any suggestions on what might be causing these to fail and put the car in limp mode? And will the codes I eventually read be able to point to how to fix?
Thanks,
Sarah

You don’t need a code reader to pull the codes on your OBDI Chrysler.

You cycle the ignition key off and on three times, and Check Engine light flashes the codes.

http://straighttalkautomotive.com/OBD1/chrysler-OBD-I.html

Tester

The problem could be a faulty speed sensor.

The flashing check engine light faults will show you the faults in the PCM but not the faults in the TCM, ABS, BCM or airbag module. For TCM faults you will need a scan tool that can access the transmission control module.

If you have an output speed sensor fault after replacing the sensor check for broken wires near the connector. The wires may not appear to be broken because the insulation looks good, gently pull on each wire, if one seams to stretch easy the copper strands in the wire are broken.