Heater Air not Hot, but Blowing

[newoldolds88]

Purchased a 92 Delta 88 R in June. Heater worked, but no a/c. Mechanic replaced switch and relay for a/c, but said in order to keep a/c running, needed to hold slider switch for cold--warm air to far left (cold) else a/c would not engage. He said he could "disengage" system so that I would have a/c for summer and to return in the Fall after he found replacement control assembly (box-like with turnswitch for defog, defr, vent, etc.) for dashboard so it would be 100% operational. I told him to disengage for summer.

A/c worked perfect in summer. Meantime I found replacement part and assisted engineering friend in installing it in dashboard. (Three electrical connections and rubber vacuum connector). Replaced in dash and tested a/c. All sttings worked perfectly, except not blowing hot air for heat or defrost or at all. Blows only cold air at all fan settings. I also checked heater core and found both hoses in engine compartment hot, i.e., output and input into engine compartment returning fine.

What could he have "disengaged" or what else can I check as to connections, locations for problem of no hot air? That's for any assistance that can be rendered.

 

[Pastalaskan]

There is an electricly controlled heat mixing door... you might see if all the connections under the dash are plugged in. On the 98 with auto temp settings it is a motor control the control the output temp to the set temp.

Mark