My rear heat just blows cold. How does the rear heat work? the rear blower works, but blowing cold, is there a valve to let the coolant go to back coil for heat or is there a damper located at the rear coil?

 

Hi fr420, welcome to the group. My '96 has a vacuum controlled valve close to the rear coil that controls flow. You might try working the valve's arm back & forth to see if you detect hot flow thru it. Should it need replacement I've read the lower priced all plastic units don't last long. The motorcraft valve is worth the extra cost ($8 vs $25)