i have a 2500 Dodge Ram with the cummins with 292,000 miles on it. Last year we were having problems with the tc going in and out of lockup all the time, during the winter. It stopped doing it once the temperature got above 40 degrees. now over the past week the temperature has gotten below 40 degrees for the first time and it has been coming in and out of lockup again. Is this the tps or is it a temp sensor in the tranny? Any help would be great.

 

My 98 does the same thing. I don't need to look at the temp to tell when it gets to 49f.

When it gets colder, I'll cover most of the cooler. That kept it from happening most of the time last year. Also, seems to do it mostly when pulling a long grade at low 25-30 mph. (My county road to the house)

ED

 

Sounds like the temp sensor. Easy way to check is to unplug the sensor lead and jump across the wires with a 1000 ohm resistor. This tricks the pcm into thinking the tranny fluid is 70°. Leave it in for the winter if it works but I wouldn't tow heavy in hot weather with it jumped as you won't know if the tranny is over heating.
On your '95 the sensor is in the outlet line to the cooler, about a foot forward of the tranny, driver's side.

I see you have an aftermarket TC, do you also have a tranny temp gauge?