no heat in my 88 comanche vaccum Question

[mjburch]

my jeep has no heat comming out of the box..

 

i zip tied the heater control valve open..

 

how do you cheack to see if the vaccum is working??

[Pete M]

is anything coming out the windshield vents?

[mjburch]

no theres nothing comming out.

 

i move the heater control settings and nothing happens..

 

do u think that since i did a a/c delete kit that may affect the heat box?

 

i belive it has something to do with the vaccum but idk how to test it

[Pete M]

A/C delete kit?

 

 

There are vacuum testers out there (try searching at harborfreight.com) check the condition of the vacuum canister. should be up behind the front bumper on the pass side. The lines going to it seem to fail early. Also check your front axle lines if 4wd. how well does your truck idle?

[jmderyke]

at your heater control valve in the engine compartment theres the vacuum line feeding to it check at the valve. Turn heater to on and then go pull the vacuum line at the control valve and put your finger on it there should be vacuum. I'm not 100% sure that there is vacuum applied when heater is switched to on it maybe applied to when switched to off. Either way you should be getting vacuum on one of those settings. If not trace back to inside the compartment and start checking vacuum lines and believe theres a diaphragm near the control box if I remember right. If your controls are working right then your cooling system may have air in it or your heater core could be blocked??

[J B Cuz]

In my 87 the vacume is always on if the heater control is in any position other then off.

 

J B Cuz