I have a 89 se when I got the car the temp gauge would not work at all and I was also having a problem with the speedometer so I replaced it. After installing the new guage cluster the temp guage would work but sometimes it will read hot I mean like pegged above hot other times in doesnt read al all sometime it works correctly Does anyone have any idea what the problem could be Is there some kind of computer or relay that could be bad.

 

sounds like a bad ground or sending unit

 

I replaced the sending unit in the block today same problem were do I look for the ground so that I can check it

 

i have exactly the same problem. Temp and speedo not functioning properly on an 89 SE. I haven't fix the problem yet though. could this be a common problem for 89's?