Question about 88 K5 defroster
#1
Question about 88 K5 defroster
I have a 1988 K5 Blazer, the question is, when the truck is not running I have plenty of air flow from the defroster, but when the engine is running there is hardly any air flow. I have checked all fuses, air ducts are clear, anyone know what I might be overlooking?
#2
Sounds like one of the doors in the hvac system is closing off the air flow. The doors are vacuum operated and will return to a neutral position without vacuum.
#3
I went outside to check and see if it made a difference if I was at a idle or revved up and it does not change.
I will check the vacuum tommorrow, I noticied a couple of line looked slightly cracked the other day.
I will check the vacuum tommorrow, I noticied a couple of line looked slightly cracked the other day.
#4
Take a look at the attached vacuum diagram and system schematic. It'll give you an idea of what is supposed to have vacuum and what isn't for a particular mode.
The fact that it doesn't change from idle to wide open throttle makes since if the check valve in the system is doing its job. You likely have a leak in the system somewhere beyond the check valve, but it isn't enough to allow the vacuum to drop during quick WOT stabs.
The fact that it doesn't change from idle to wide open throttle makes since if the check valve in the system is doing its job. You likely have a leak in the system somewhere beyond the check valve, but it isn't enough to allow the vacuum to drop during quick WOT stabs.
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