What did you do to your NNBS GMT900 Tahoe/Yukon Today?

[kbuskill]

New ground cable with sensor in the last 6 month, both battery's are less than 2yrs old (odyssey extreme agm's 34/78), big 3 upgrade, plus a new nbs style positive cable direct from alternator to 2nd battery, I do loose about .2 amps from alternator to battery I get like 13.78 testing alternator direct to ground bracket, then I get 13.58 at either battery

when I was testing it yesterday I (think) it was showing fuel economy mode-active when the voltage was down to 11.3v, which it should not have been active as far as I can gather which is making me lean towards a firmware issue. There is a bit of technicality to how the rvc system works like how much battery charge it shows, what the battery temp is estimated at etc, etc.

Strange... Didn't you say you unplugged the RVC sensor and it didn't make any real difference. Seems like unplugging it would make it go to a pre set/default charge mode.

Keep is posted on what you figure out... its definitely strange.

 

[Doubeleive]

Strange... Didn't you say you unplugged the RVC sensor and it didn't make any real difference. Seems like unplugging it would make it go to a pre set/default charge mode.

Keep is posted on what you figure out... its definitely strange.

It didn't at first with everything going full bore, after a couple restarts and a little break it started giving 13.8-14, I tested it again this morning with the rvc sensor still unplugged and voltage was running normal 13.8v, fuel economy mode was off, battery was reading 14+v. I am going to take it for a little drive here in a bit and see what it does

 

[kbuskill]

It didn't at first with everything going full bore, after a couple restarts and a little break it started giving 13.8-14, I tested it again this morning with the rvc sensor still unplugged and voltage was running normal 13.8v, fuel economy mode was off, battery was reading 14+v. I am going to take it for a little drive here in a bit and see what it does

Do you think it is heat related???

In other words, when it's cold does it seem to charge better and once it's up to temperature, like after driving for a while, does it seem to charge less?

 

[iamdub]

Tested the control functions of the ALC system.

Snipped the wires to the locked-up compressor and stabbed in my DVOM leads:




Jumpered the blown fuse instead of using the $5 replacement I bought yesterday as a Guinea pig:




Disconnected and propped up the height sensors with some wrenches to simulate a sagging rear end:




I wasn't sure if it'd activate the compressor with just the key on so I started it. After a few seconds, the DVOM went from "0" to 14.xx VDC. I removed the wrench on the driver's side and slowly lowered the sensor arm and the DVOM went to "0". Lifted the arm again and held it and the DVOM went back to 14.xx VDC.

Best I can tell, the system is ready for the new compressor! It was supposed to be delivered today but I doubt that'll happen because of the storm. Oh well, at least I have some diagnostics out of the way.

 

[kbuskill]

Tested the control functions of the ALC system.

Snipped the wires to the locked-up compressor and stabbed in my DVOM leads:

View attachment 226653


Jumpered the blown fuse instead of using the $5 replacement I bought yesterday as a Guinea pig:

View attachment 226655


Disconnected and propped up the height sensors with some wrenches to simulate a sagging rear end:

View attachment 226657


I wasn't sure if it'd activate the compressor with just the key on so I started it. After a few seconds, the DVOM went from "0" to 14.xx VDC. I removed the wrench on the driver's side and slowly lowered the sensor arm and the DVOM went to "0". Lifted the arm again and held it and the DVOM went back to 14.xx VDC.

Best I can tell, the system is ready for the new compressor! It was supposed to be delivered today but I doubt that'll happen because of the storm. Oh well, at least I have some diagnostics out of the way.

There seems to be some kind of time delay built into the system. I noticed this when I was adjusting my level sensors after lowering. You move the sensors and it takes several seconds before the compressor kicks on or the exhaust valve opens.

If I ever do the TBSS bags I plan on hooking up a switch to the exhaust valve so I can have the option to dump it when I park if I choose to.

 

[Rocket Man]

Tested the control functions of the ALC system.

Snipped the wires to the locked-up compressor and stabbed in my DVOM leads:

View attachment 226653


Jumpered the blown fuse instead of using the $5 replacement I bought yesterday as a Guinea pig:

View attachment 226655


Disconnected and propped up the height sensors with some wrenches to simulate a sagging rear end:

View attachment 226657


I wasn't sure if it'd activate the compressor with just the key on so I started it. After a few seconds, the DVOM went from "0" to 14.xx VDC. I removed the wrench on the driver's side and slowly lowered the sensor arm and the DVOM went to "0". Lifted the arm again and held it and the DVOM went back to 14.xx VDC.

Best I can tell, the system is ready for the new compressor! It was supposed to be delivered today but I doubt that'll happen because of the storm. Oh well, at least I have some diagnostics out of the way.

Good work. How are you holding up down there?

 

[iamdub]

There seems to be some kind of time delay built into the system. I noticed this when I was adjusting my level sensors after lowering. You move the sensors and it takes several seconds before the compressor kicks on or the exhaust valve opens.

If I ever do the TBSS bags I plan on hooking up a switch to the exhaust valve so I can have the option to dump it when I park if I choose to.

There has to be some kind of delay in response, otherwise the compressor would kick on every time you hit a dip and the suspension compressed. I figured out that there was a delay of at least 5 seconds after starting it cuz I had 5+ seconds of suspense and disappointment after I cranked it up. I moved the sensor arm very slowly and paused ever so often while I watched the DVOM until I was satisfied that it was responding as it should.

Oh- The factory air line actually fits a little loosely inside the Air Lift line, but the flared end is kinda tight and should be plenty sufficient for testing with a clamp on it. If it all works as planned and I'm ready to make it permanent, that size difference will be convenient in allowing space for a healthy packing of epoxy.

Short of the compressor's performance with the bags, I'm optimistic. Soon enough, I should be able to give you an idea of how the compressor will do so you'll know if you could pump up the deflated TBSS bags within a reasonable time frame.

 

[iamdub]

Good work. How are you holding up down there?

Thank you.

I'm actually really enjoying the weather! I had breakfast and was on the patio with coffee and laptop for 8AM just so I could enjoy the 75° temp and steady 20MPH breeze! Had a few spotty and light showers that were more like a sideways mist because of the wind but now it's a steady light rain. It's only gonna get worse from here. I'm not expecting anything detrimental at all, just stiff gusts and lots of rain.

The cooler temp is why I'm staying out here tinkering. I was even gonna do the trimming for the Belltech alignment cams but realized I'd need the strut outta the way, so I just took notes and put the wheel back on.

 

[iamdub]

Realized the mesh of the grill could be popped out so I grabbed a plastic trim tool and made quick work of that to get an idea of how a black grille would look:








I may spray the removed pieces the same black that I paint the wheels (satin/low-gloss) or just trade someone my chrome for their factory black ones. I think I'd prefer that chrome outer ring to be black as well instead of color-matched. I have some aluminum expanded metal that's similar to stucco mesh. I may use the pieces I took out as a mold and make my own aluminum inserts, because racetruck and boredom.

 

[Doubeleive]

Do you think it is heat related???

In other words, when it's cold does it seem to charge better and once it's up to temperature,like after driving for a while, does it seem to charge less?

well something is up, left the sensor unplugged,I just went for a drive voltage was good 14+, until I exited the freeway, with 1 seat cooler running, headlights, a/c front rear voltage dropped down to 11.8v sitting at the light on the offramp, went to the post office left it running it sat pretty much right on 12v idling, then on the freeway back it went back up to 14+.
so just to rule it out I am going to pull both battery's and have them load tested and go from there. it is 93deg