Under -heating problem.
Hello, I have had a 1988 B2000 from new. It has done me proud but lately after a radiator change the heater temp is low, all the coolant is new. The temp gauge reads at about a third of the way up the scale, (No degreee readings) whereas it always used to read about half way up. Any help will be appreciated.
It sounds like your thermostat is stuck open. The gauge should be around where it was.
If you are getting heat as always, it might just be the temp sender for the gauge has finally worn out. After all, if it hasn't ever been changed it's 25 yrs old, and they do go bad through many heat cycles. Or, are you sure the correct radiator and thermostat were installed?