What did you do to your NBS GMT800 Tahoe/Yukon Today?

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Rocket Man

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Took it to the mechanic today, he checked some basic things. Does anyone have any recommendations on a good 6" cone filter? I'd rather it be the dry style. The one in my Volant is so filthy, can't even see through it, plus the rubber on the neck is starting to crack. He also told me he thinks the maf is too close to the box(mounted on it), and too far away from the tb to get a good correct reading to send to the pcm. I've had a soft maf code since the original 6.0/cam swap was done. He thinks it being mounted on the cold air box might be part of the issue. Told me to get a new filter, and to clean the maf really good. If those aren't the problems it may be the pcm has a bad board in it. This kind of makes sense to me. The original tuner told me he couldn't program the pcm in the truck, that it kept losing communication with his laptop. This happens to me all the time. Constantly loses communication with the Tech 2 AND with my scanner. One time I had gotten a bunch of crazy random codes when I plugged in my scanner. So--try cleaning the maf, get a new cone filter, and if that doesn't solve the problem, a new pcm.
So........anyone know of a good 6" dry cone air filter?
Just look for one from a reputable manufacturer, that’s a universal size. Here’s a K&N dry cone.
 

Rocket Man

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Bad pressure switch perhaps? If it's taking refrigerant and not cycling/compressing, it's possible the switch is bad and keeping the compressor from kicking on. It's cheap and easy enough to replace that it might be worth it to fire up the parts cannon before you do something more labor intensive.

So I just got the part I ordered from RA but it’s not right. I looked under refrigerant pressure switch and theres 2 categories- the ones that are compressor mounted and one that says ac system mounted that looked like the one on my accumulator. I ordered that one. Now I see there’s a category called ac clutch switch. And under there are the ones that say accumulator mounted. So I ordered a GM genuine. I just checked the compressor visually snd it’s not cycling on. My Tech2 says the ac pressure is out of range so it won’t allow me to cycle the comp on. Pics attached. I’m hoping it’s the switch. Not sure if “cmp sensor” is compressor sensor but the high to low and low to high read the same, at 816 or something. On the side of the old switch it says on at 40, off at 20 psi.
 

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Rocket Man

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Bad pressure switch perhaps? If it's taking refrigerant and not cycling/compressing, it's possible the switch is bad and keeping the compressor from kicking on. It's cheap and easy enough to replace that it might be worth it to fire up the parts cannon before you do something more labor intensive.

So I just got the part I ordered from RA but it’s not right. I looked under refrigerant pressure switch and theres 2 categories- the ones that are compressor mounted and one that says ac system mounted that looked like the one on my accumulator. I ordered that one. Now I see there’s a category called ac clutch switch. And under there are the ones that say accumulator mounted. So I ordered a GM genuine. I just checked the compressor visually snd it’s not cycling on. My Tech2 says the ac pressure is out of range so it won’t allow me to cycle the comp on. Pics attached. I’m hoping it’s the switch. Not sure if “cmp sensor” is compressor sensor but the high to low and low to high read the same, at 816 or something. On the side of the old switch it says on at 40, off at 20 psi.

Edit: I see from alldatadiy that there’s a low pressure and high pressure switch. The low is on the accumulator and the high is mounted in the compressor and requires evacuating the system. I’ll try the low pressure switch. I feel like I’m fumbling in the dark.
 

NoReverseYukon

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I had some good luck at the junkyard today - 3 Yukon Denalis.
And 2 still had their instrument cluster. IMG_20220813_220816627.jpg
The 2000-2002 cluster lit up fine on the bench.
I need to figure out how to power up the 2003-2006, but if it tests good I will probably be putting it up for sale here.
 

Fless

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I had some good luck at the junkyard today - 3 Yukon Denalis.
And 2 still had their instrument cluster. View attachment 377908
The 2000-2002 cluster lit up fine on the bench.
I need to figure out how to power up the 2003-2006, but if it tests good I will probably be putting it up for sale here.

2003-2006 cluster pinout attached.
 

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clandr1

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So I just got the part I ordered from RA but it’s not right. I looked under refrigerant pressure switch and theres 2 categories- the ones that are compressor mounted and one that says ac system mounted that looked like the one on my accumulator. I ordered that one. Now I see there’s a category called ac clutch switch. And under there are the ones that say accumulator mounted. So I ordered a GM genuine. I just checked the compressor visually snd it’s not cycling on. My Tech2 says the ac pressure is out of range so it won’t allow me to cycle the comp on. Pics attached. I’m hoping it’s the switch. Not sure if “cmp sensor” is compressor sensor but the high to low and low to high read the same, at 816 or something. On the side of the old switch it says on at 40, off at 20 psi.

Edit: I see from alldatadiy that there’s a low pressure and high pressure switch. The low is on the accumulator and the high is mounted in the compressor and requires evacuating the system. I’ll try the low pressure switch. I feel like I’m fumbling in the dark.

You could try jumping the plug for the low side switch with a paperclip or something similar to see if it forces the A/C clutch to engage. I probably should have mentioned this sooner... Skip to about 1:30 in the video.

 

Rocket Man

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You could try jumping the plug for the low side switch with a paperclip or something similar to see if it forces the A/C clutch to engage. I probably should have mentioned this sooner... Skip to about 1:30 in the video.

I’ll try that. Do you know if there’s a way to check the high pressure switch?
 
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