NO DEFROST

[JOE.C]

heater works fan works and ac also but when i switch to defrost no air blows out what could be problem.?

[Rye]

Make sure all of your vacuum lines behind the dash are hooked up. I had one come loose last winter and lost all my heat until I found out what was causing the problem. Needless to say it was a cold drive to work each day.



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76 Wag 401 Th400 Q-trac w/ low range
3" body lift 32" BFG's
Dual exhaust
My first 4x4!!!

[joe]

What year FSJ we talking about here Joe?
Don't know what the late (86+ something)ran for heat/def controls but the earlier ones used vacuum lines to activate the controls. Look/feel on the back of the heat/def/air selector and see if the vacuum hose is connected to the def terminal. Also look under the dash passenger side dash for a round flat thingie(def vac diaphragm) and see if the hose is connected. Long legged passengers seem to have a knack for getting their feet up in there and pulling it loose.
Also just cause it is still connnected pull the hose off and at least inspect the ends...it may be leaking. Stuff's like $0.20/ft, worth replacing.

[JOE.C]

<BLOCKQUOTE>quote:</font><HR>Originally posted by -joe:
What year FSJ we talking about here Joe?
Don't know what the late (86+ something)ran for heat/def controls but the earlier ones used vacuum lines to activate the controls. Look/feel on the back of the heat/def/air selector and see if the vacuum hose is connected to the def terminal. Also look under the dash passenger side dash for a round flat thingie(def vac diaphragm) and see if the hose is connected. Long legged passengers seem to have a knack for getting their feet up in there and pulling it loose.
Also just cause it is still connnected pull the hose off and at least inspect the ends...it may be leaking. Stuff's like $0.20/ft, worth replacing.<HR></BLOCKQUOTE>

[JOE.C]

[QUOTE]Originally posted by -joe:
What year FSJ we talking about here Joe?
Don't know what the late (86+ something)ran for heat/def controls but the earlier ones used vacuum lines to activate the controls. Look/feel on the back of the heat/def/air selector and see if the vacuum hose is connected to the def terminal. Also look under the dash passenger side dash for a round flat thingie(def vac diaphragm) and see if the hose is connected. Long legged passengers seem to have a knack for getting their feet up in there and pulling it loose.
Also just cause it is still connnected pull the hose off and at least inspect the ends...it may be leaking. Stuff's like $0.20/ft, worth replacing.[/QUOTE sounds like i might have knocked something loose, just under there had to remove heater core to get at exhaust manifold bolt. the rig is an 1980 j20 thanks to all for your help. joe.c