Air cleaner. Thermac details required.

[BoK5]

I have a 1989 K5 Blazer with standard fuel injection.
My question is about the thermac actuator. How is it operated on a 1989 K5?
This is how it looks


There is no vacuum motor on the top side.
There is no air cleaner temperature sensor.
As it is now, it will only take in warm air.

 

[dyeager535]

TBI trucks didn't run an air inlet temp sensor.

That is an odd THERMAC setup, but I've not messed with the later ones either. Earlier was pretty simple, vacuum pulled on the diaphram when the temp was right in the air cleaner, but I suspect you already know that.

Doesn't seem like what you show would be very effective, but it doesn't look particularly cobbled together either. And if the air cleaner base has no provisions for a THERMAC temp switch, even more indication that isn't how they operated and that it was not messed with.

 

[Big Ray]

I have been known to wire them open....

 

[Sheepdog]

Thats exactly how mine looks on my 89 burban. Theres a spring in there that is holding it closed it was prob supposed to work off heat. I took my spring out then it made rattlin noises. So then i gutted it. Still passes smog here in CA. If that valve opens when motor is hot its prob workin like its designed if not id remove the valve.

 

[BoK5]

Thanks a lot for your replies.
I just might fix it in open position.

 

[Sheepdog]

Heres how I fixed mine,,,,,

 

[BoK5]

Picture tells the story. Thanks.

 

[southernspeed]

and that is the straightest, most un-crumpled and un-bent stove pipe I've ever seen!

 

[Keitha]

I pinned mine open. You will probably need the stove pipe to pass visual smog, but they don't check the operation.