My 88.5 TR heater used to work, but no heat now, does someone have an list of possibilities, I twist my own wrenches. BTW, blower and A/C work fine. Thanks to all you who have been down this road before.
Are you getting current to the water valve, located in the passenger footwell on the right side? +12 v. shuts the valve, so when the temp control is set for heat, the current should cut out, thus opening the valve and supplying heat. The ECU will then cylce the valve on and off to maintain the desired temperature. The shop manual is invaluable, as it explains how the system works, and gives instructions on how to easily check all the sensors that are used (a bad sensor could be telling the ECU that you already have heat)...There also relays located in the center of the dash, below the blower unit. They can be accessed by removing the trim panel by the accelerator.
