Humfreeze

Heater core went bad and Had to replace. I tore the entire dash out as explained in the Service manual and reinstalled. I started vehicle up after the installation and got an ABS SERVICE light that will not go out. First day the heat was fine as it idled in the driveway but when I took it out on the road as the engine now had higher RPM on it the heat would quickly go away and blow only cold air. When you stop the heat returns at low RPM. Yesterday I changed the thermostat, started vehicle up and the Water Temp and OIL Temp gauge all read normal temps with massive amouts of hot air pouring out of vents. ABS Service light still illuminated... WTF... Drive to work this morning get on interstate -- no hot air at all.. Stop and let car idle on flight line-- no hot air at all.. Opened up the hood and quickly realized that A/C compressor is running and the cooling fans are also running all the time any time the car is running. Diagnosed the code and it is a CODE 76--Lateral Accellerometer Fault. Now I am at wits end. Any help is greatly appreciated. None of these problems existed prior to changing out the heater core so I am statrting to think that maybe a wire under the dash is shorted out. Thanks
FREEZE

garwood94

I have not replaced my heater core but I have lack of heat just like you do. I get heat sitting in the driveway but after going a few miles the air gets cooler and cooler, as if the heat was being shut off of the heater core... I'll be watching your post to see if anyone steps in with the answers...

WW7

This won't solve your electical problem but it may solve your heat problem. It sounds like you haven't burped your system completely, you may have air in the system thats causing the heater problem.You also need to state what year car you have , it helps us out to know...WW

Humfreeze

Please search for the posting titled "Overcooling problem". It was an extensive blog of what finally solved the problem.

Hope this helps

Freeze