No Heat Now!

[Mike523]

I have no heat in the cabin.

I just finished replacing the starter, rotors, timing idler pulleys, front crank shaft seal . . . . . .

I did remove the heater valve on the firewall, cleaned it & reinstalled it during my mini overhaul.

With the temperature set high, the cable won’t push out to open the valve.

If I manually remove the cable and open the valve, the heat is there. All lines off the valve are hot with coolant.

When the climate control is set on Auto, it won’t start the fan when the coolant is cold, so that’s still working normal.

I’m assuming that it is not a coincidence that it is not working after having so much of the top end of the engine apart.

What do you guys think?

[wwest]

Assuming this is an early model, 92, say, the cable that controls the water flow valve is mechanically coupled to the airflow heat/cool mixing vane servomotor inside the plenum. If you block the water valve open manually and can still get reasonably cool airflow in max cool and hot airflow in max hot then the mixing vane and its servomotor are still operational and the mixing vane end of the cable has come off the pin inside the system.

Not sure how easy or hard the fix will be if that is the case.

Back when I was driving our 92 I would tie the water valve closed during the summer months to reduce the A/C load and increase fuel economy. The RX series always has it open, no valve at all, and seems to work fine (mostly) relying only on the mixing vane for airflow temperature control.

I am currently in the process of obtaining a 12 volt water control valve from an 300D MB turbo diesel to install in the RX so the hot water flow will always be off anytime the A/C compressor is enabled.

[Mike523]

Sorry, yes it's a 92. I have a manual and I'll look to see what the other end of the cable looks like, where it is and how hard it is to get to. Maybe I messed up the other end of the cable when I removed the valve.

Thanks!!

Mike