s14 heater won't work

[KC224]

Picked up a 2nd s14 and the heater doesn't work. it blows cold (ac) air and cool air with ac off, change it to heat and it stays the same.

I checked the valve on the hose and found the cable was off, I reconnected it and slide it from cold to hot, the valve doesn't move. I tried disconnecting it and put it down manually to try to get heat but nothing. Both top and bottom hoses are warm.

When I go to my other s14 I can hear clicking noises when I change it from cold to hot on each notch it makes a click noise. With the new one it doesn't do that. Tried swapping the control unit just to rule that out, no luck. So what controls that cable to the valve? Couldn't find it behind the radio like everyone says.. Maybe I'm blind :-/ Don't know what else to try.
Thermostat? Heater core? what do you guys think?

My temp gauge is also pretty funny, as it will run cold some days and other days slightly warm, but even then to the touch(motor) it's not as hot as my other s14 that reads normal.

[zerodameaon]

The valve sounds like its broken off the shaft or there is some kind of blockage stuck around the valve or inside the core/hoses somewhere. Take the hoses off at the firewall and stuck a garden hose on it and pump some water through it and see if it flows free.

[racepar1]

For your heating problem, It sounds like it may be a blend door actuator. You moved the valve by hand, both hoses were hot, and the heater still didn't work. Also you didn't hear the doors moving under the dash. That tells me that the blend door actuator isn't functioning for some reason. It sounds like you have a problem with the cable to the heater valve as well though.

For your temp issue, change the thermostat. The previous owner was probably a jackass and took it out.

[KC224]

Hrm alright thanks guys I'll try to check those things.

[ReLiC]

I would try swapping the hvac unit since you have one from your other s14.