I've got a 1997 V6 with a couple of different A/C issues. One is what sounds like the blend door actuator which there are a myriad of threads on. Although I"m thinking my 1997 has a different glove box and thus the through the glove box trick doesn't work? Do I need to remove the dash?

Anyway, the bigger issue is that the compressor continuously cycles on and off. 1 second on, 3 seconds off, repatedly. RPMs don't seem to make a difference. If I disconnect the low pressure switch, it doesn't come on at all. I jumpered that switch to force the compressor on and it runs okay. But not blowing very cold. So I'm thinking low charge? I picked up a can of r134 with a built in guage but it doesn't seem to fit the low pressure port. This is the one on the accumulator right?

Ok I'm officially an idiot. Once I figured which end of the hose to connect to the port I was golden.

The charge was definitely low, so I charged it til it was at about 43 psi or so with ambient outside temperature of 75. It's blowing cold now, but not THAT cold (75 or so per my BBQ thermometer). But this is all coming out of the defrost due to the suspected actuator problem ... so I wonder if that is related? Would the actuator issue cause some of the cold air to escape / mix with room temperature air?

Also, am I on the right track on the actuatir? My truck has the dial style controls with Max A/C, A/C, and a mix of vents and foot on the A/C section, then settings for all vents, mix of vent and floor, all floor, defrost. Anyway, on Max Cool the air comes from the defroster and the floor. Same thing on the A/C setting. On the third setting it comes from floor, defroster, and a tiny amount from the vents.

Does this sound like the blend door actuator issue?

 

I would suspect a vacuum issue rather than a problem with the temp door. Do you have vacuum to the hvac control module?

Here is the diagram/schematic for your HVAC:

 

Good to know. I haven't dug into it at all yet ... just been reading here. So is it safe to say the temp dial (red and blue) is for the temp door and the dial I am talking about is vacuum?

And can I get at all this by just removing the bezel over the A/C controls, radio, etc. or will I still have to remove the dash? Lastly is a vacuum guage all I need to troubleshoot this?

Just had another thought ... my 4WD currently does not work (my next project) which in my reading sounds like it may be vacuum related as well ... so maybe I have an overall vaccuum issue ...

 

I have the same prob. but i have dug into it, i just traded a 85 s10 for this 97 bravada smartTrak and its defly. 2wd all the time dunno have but def. is. So, i found the vac line he's talkin about its under the intake and goes to the driver fender into the ball then the firewall through cab, if your window to face to floor switch ( sry bout the terms) is working work VAC is working, the blue and red switch is my prob. the HOT FIRES OF HELL burn my face and feet b/c i can't find out how to make it pull COLD AIR.

 

Okay I for sure get the dunce of the year award. The vacuum line from the intake to the ball attached to the hood by the driver's side was disconnected and just sitting there. Hooked it back up and vents work fine.

Pretty good. Went from "take the whole dashboard out" to "connect a vacuum line with your fingers" overnight.

 

yea just went out checked the Images he posted and flipped my hoses around (ladies) and the damn think "was" blowing COLD but it stopped
What the hell i dunno what's going on , but i dug out half of mine dash cause you can get through the glove box on mine, but i am lose'n pressure whenever i go back and check out the refrigerant , maybe its just that low or there's a leak .....but it doesn't account for it to JUST BLOW DAMN HOT AIR !!!! right

well glad you don't have to go as far as i have to. thx for posting this cuase i'm new and dont know how to post right now, thx jon street, outta FLA.

 

Well I *may* still have a problem. It's working better now but still not compeltely consistent. And the 4wd went from 2Hi to 4Hi but now it's stuck there. Didn't want to risk trying 4Lo. So I'm thinking I still may have a vacuum issue somewhere.

Are there specs on how much vacuum I should get at different points?

 

the dealer may i'm not sure, damn ppl in the club kept me till 3am hell time for bed, wel in the morning i'm going to dig in and see if i can find out whats up with mine, i say the switch but my boy has a shop and he say's the act. door as well. who knows? but i know there's someone out there thats had the same prob, i know me and you can't be the only ones and mines the Bravada...soo...

 

Oh you should change the name of the post or re-name it to A/C problems, later

 

Finally got back to this. Vacuum was good all the way to the control module. Gray vacuum showed the same as the manifold. What did happen was that I was messing around with it, it seemed the connection between the orange thing that the vacuum tubes all go to and the plastic part was a bit loose. I squeezed it together and MOST things are working right now. Still a bit of an issue with heat/defrost vs. defrost only in that they both blow out of floor and defrost but I'll take it for now.

Question. Should I replace the vacuum module? If so is it the whole thing including the orange part or just the plastic part with the dial connector, etc.?