Location of heater and AC actuator?

[gmbellew]

The AC, heat, and defrost in my 1990 v1500 suburban works as it should except the air flow is split between floor and dash on the AC, MAX AC, vent, and heat settings. The defrost works as it should. Based on looking at how the system operates, I think there is an issue with the heater and AC actuator. Maybe a vacuum line disconnected or a bad actuator. Where is this actuator located? I am trying to figure out how deep of a dive it is to verify if the actuator or door are the problem.

 

[C10MixMaster]

The AC, heat, and defrost in my 1990 v1500 suburban works as it should except the air flow is split between floor and dash on the AC, MAX AC, vent, and heat settings. The defrost works as it should. Based on looking at how the system operates, I think there is an issue with the heater and AC actuator. Maybe a vacuum line disconnected or a bad actuator. Where is this actuator located? I am trying to figure out how deep of a dive it is to verify if the actuator or door are the problem.

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[gmbellew]

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So it looks like it is under the hood?

 

[C10MixMaster]

So it looks like it is under the hood?

most of it is under the dash on the passenger side. Except the vacuum motor #266 is in the cowl behind the blower motor and the vacuum line E comes through the firewall from the engine compartment. Remove the glove box you wi get a better view.

 

[gmbellew]

most of it is under the dash on the passenger side. Except the vacuum motor #266 is in the cowl behind the blower motor and the vacuum line E comes through the firewall from the engine compartment. Remove the glove box you wi get a better view.

Thanks. I think actuator 269 is the one that needs some TLC.

 

[C10MixMaster]

Thanks. I think actuator 269 is the one that needs some TLC.

That actuator has 2 hoses going to it. H and I so test both sides of that one. Also where that actuator connects to the door there is a plastic piece 168 that is known to break.

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[gmbellew]

That actuator has 2 hoses going to it. H and I so test both sides of that one. Also where that actuator connects to the door there is a plastic piece 168 that is known to break.

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Thanks for the help. I used the heat today and very little air comes out of the dash vents on heat, so I think I may have vacuum on the heat side of the actuator. Based on how the system operates with vent and AC settings behaving like bi-level, I think I lost vacuum to the ac actuator with the tan line, but I will try to check out the plastic clip to make sure it is still functional while I have my head under the dash.

 

[Craig 85]

My issue was part # 265. All my vacuum pods and lines were good. Of course it's no longer produced. Someone else was able to use Vasaline to lube it, but that didn't work in my case. I had to buy an NOS control unit that included the valve to fix my problem. GM 16034591 or ACDelco 15-71268.