I have a 1996 2wd Cherokee with the 2.5L carbed engine in Beijing China...
when i was given the jeep the speedo didn't work. i got a replacement cluster that had a tach, however the speedo was broken on it. i tested this cluster on a friends xj and it reacted the same way.
After searching on this forum, I took my stock cluster apart and cleaned all the contacts very well with rubbing alcohol. i put it all back together and it worked great... for about 3 days. it started to drop to zero off and on while driving until it totally died. i took it back apart and cleaned everything again and it worked great... for about 3 days... same reactions until nothing. Again, i did the same thing and it was good for 3 days. Also, this last time i noticed that when i turned on the AC the speedo dropped to zero... then when i turned it off, the speedo worked fine again. Not sure what is going on, but im tired of taking the dash apart and would like to know my speed. only the speedo is doing this, all other gauges are 100% great.
Also, i put on a new speed sensor on the tranny so that has no issues.

any guesses????

 

id try bending the contacts out a little on the connector ,maybe getting a better contact will help