So when I select defrost no heat is coming out at the window. Truck has great heat otherwise. So when I make the selection to defrost what is the logical steps of what is supposed to happen? What should I be looking for here...
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.
Not Defrost
- Thread starter Justin Fleming
- Start date
Check for vac at the diaphram near the gas pedal on the heater box. That controls the flap that directs the air to defrost or foot.
I have no vacuum at this location when defrost is selected. Where does this get the vacuum from or where is the next connection. It looks like the like goes towards the steering column but I loose it
So digging into this further, and reading similar post on multiple boards, What I have noticed is that the previous person for what ever reason removed the cruze control unit. See attached photos. The large hose I assume goes into the firewall and probably down to the brake switch, the little one with the T installed used to go to the cruze unit also. So the question is do I just take the port on the T to manifold vacuum? does there need to be a inline diaphragm as I thought when it went down to the cruze unit it was T again, with one leg going to the cruze and the other leg had some sort of inline device and then went to manifold possibly??
Should be a round ball above the blower on the firewall. 2 vac lines to it.
Larger from vac source on engine, other one smaller goes thru the firewall to the AC/heat control selector and branches out from there depending on selector position.
Any vac lines going to cruise control cap off or eliminate.
Larger from vac source on engine, other one smaller goes thru the firewall to the AC/heat control selector and branches out from there depending on selector position.
Any vac lines going to cruise control cap off or eliminate.
This truck must be different. It is a 1987 fuel injected truck.
That small vac line at the top of the firewall running across, where does it go?
one end goes to a vacuum ball against the driver side fire wall, the other end goes all the firewall and enters the cab on the passenger side. I believe this is the T that I need to add vaccum to. I just was not sure, and if it would be manifold vaccum or not
Engine vac to that ball then the from the ball thru firewall to supply the a/c controls with vac.
The ball is just a reservoir for vac when engine demand is high and vac is low.
The ball is just a reservoir for vac when engine demand is high and vac is low.
Either way that is the vac supply for the AC
just connect the open end of the tee to manifold and you so be fine.
So I tapped the T fitting to manifold vacuum, fixed a break in the hard plastic line and now I have defrost....
