No heat coming out of Vents!!

[86Monte4.3]

Hey guys I just bought a 1986 Monte Carlo 4.3 TBI with a non A/C heater only box and I turned on the heater and it only blows out at the floor and defroster vents.. I checked out all the controls everything moves like it’s suppose to and still nothing so I’m stuck and don’t know what else to do any suggestions will be highly appreciated

 

[TURNA]

Did you pull the VENT levers under the steering column?

 

[86Monte4.3]

Yes still no luck.. I replaced blower motor and blower motor resister and still nothing

 

[fleming442]

Search "vacuum selector" here.

 

[bracketchev1221]

Check the vacuum switch on the back of the control head. Scoggin Dickey has them right now, so get one fast because they are becoming unavailable. And then after that do a vacuum pull on the lines off the head unit. I can say with mine, the switch fell apart so I replaced that and still had no air out of the vents. A strong vacuum pull on the line allowed the stuck actuator to pop free after years of sitting stuck.

 

[olds307 and 403]

I bought one of the cheap ones off Ebay. They come very taped up. I actually broke the square push in that holds the two pieces together. It was supposedly an old stock bulk buy, probably getting brittle with age.

 

[TURNA]

Yes still no luck.. I replaced blower motor and blower motor resister and still nothing

Why would you replace the blower motor and resister if the blower was blowing????

Thats KINDA weird.....

 

[Longroof79]

I think Advance Auto was selling the vacuum switch if I recall correctly. I remember another suggestion was to put a small nut and bolt thru where the selector wheel clips together. Apparently it corrects the problem. I'll experiment with one of my old ones.

 

[O. D. Showtime]

I'm thinking it's something mechanical...there is no vacuum in a heat only setup...perhaps a clip is broken or a cable has come off somehow..

I've got pics at home with a dash pulled and indicating where all the cables go...I can post up but won't be until later tonight.

 

[pontiacgp]

I'm thinking it's something mechanical...there is no vacuum in a heat only setup...perhaps a clip is broken or a cable has come off somehow..


View attachment 129869

I've got pics at home with a dash pulled and indicating where all the cables go...I can post up but won't be until later tonight.

I never knew there was no vacuum with a non ac.....