Brand new to the forum and couldn't find this issue addressed specifically.

I have a '96 S10 and there seems to be some heat coming out of the vents but not blowing hot. This may be a related issue; when I switch the control dial from dash to floor vents or dash to defrost and it does not respond right and/or the blower will increase or decrease power in a delayed manner (like 5 minutes later). Seems like this could be many things, and am wondering if this could be a heater core issue (not blowing hot) or, could it all be a vacume related problem where the vents are not opening/closing properly and air is not being redirected against the heater core (since it blows warm but not hot)?

Any insights would be appreciated. Thank you.

 

I would start with a check of the vacuum system to make sure that you are getting strong vacuum to the back of the HVAC control module in the dash.

 

Thanks for the quick reply - Where and how would I do that?

 

With a vacuum gauge at the back of the HVAC control module in the dash.