New here folks ........ . Van has vacum to the dash [ runs the heat / cool ] but stays on the defrost . . With a bad back, I paid the dealer here to fix it , as I couldn't lay under the dash for extended time. . Well , now for the 3rd time in 4 years it's broken again . . Is there a known problem with this series ? . Dealer wants paid again to repair ........ ain't a gonna do it ! ! . Thanks in advance . . The original ............ Dusterman
Re: 1998 GMC Safari / Astro blend door problem
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Thanks for the offer to help. . The dealer RO merely says repair to run . . No parts needed ......... . They refused to explain other than , it works . . . In my youth I was a decent wrench , until I hurt the back . Needless to say I am not real happy with the dealer . I had just hoped to find a fix for it without all the under-dash time . Anyhowdy ..... thank you . Dusterman
Re: 1998 GMC Safari / Astro blend door problem
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Best I can say is it suggests that vacuum isn't getting to the controls. Perhaps it rubs somewhere out of sight.
That just that they fixed this with no parts as I'm not sure if it's all vacuum motor/actuator or electric controls.
It's probably just something like a vacuum hose that falls off or a wire that pulls out and with that happening three times now perhaps another tech will lenthen or rapair the spot so it won't happen again.
Re: 1998 GMC Safari / Astro blend door problem
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Vacuum is getting to the controls, the fact that I can control the heat [ vacuum ] means the control unit is indeed getting vacuum. . I am hoping that some one can share a heating / cooling diagram for this van ? . . Thanks again . . Dusterman . .
Re: 1998 GMC Safari / Astro blend door problem
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? ?There's about four different ways temp can be controlled in this pup?? Can you find a control valve on input heater hose that has vacuum going to it or not? I really don't know how this one is done but it's stickingly a vacuum problem if fixed without parts in the past. It would be that or the actuator or jammed up door, control head lost its head or who knows?
I don't have a blow-up diagram for all vehicles - some others here do - perhaps we can get a look but I still think this is a silly vac hose and perhaps if only partially leaking it can still control some of the functions,
Re: 1998 GMC Safari / Astro blend door problem
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If it stays on defrost ,then it definitely is a vacuum hose problem under the hood...the skinny black plastic hose runs along the top of the engine and usually breaks there...also gets corroded where it runs near/under the battery area.. Find the part where its broken and you can use a piece of washer hose to connect the broken ends... Also check at the vacuum reservoir under the hood,can be disconnected there or the reservoir itself can be leaking
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?There's about four different ways temp can be controlled in this pup?? Can you find a control valve on input heater hose that has vacuum going to it or not? I really don't know how this one is done but it's stickingly a vacuum problem if fixed without parts in the past. It would be that or the actuator or jammed up door, control head lost its head or who knows? 