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

[Doubeleive]

contemplating if I want to put ppv wiper arms on or not or the alternate style anyway, they stick up more though. on the silverado sierra's they are more hidden behind the hood.
also wondering if I can fit the 18 silverado arms on the 12 they are more sleek and the fluid sprayer works 10x better

 

[mikez71]

Never knew PPV had different wipers!?
I was thinking about hood mounted heated sprayers. Sucks when you have frozen wiper blades, and you can't get any spray on the windshield either.

 

[iamdub]

years ago at a very reputable shop here in town the owner told me he sometimes had issue's with the plastic ones leaking and customers coming back and having to do warranty work, so he switched to the metal ones and had no problems, might be that the plastic ones warp or something I don't know that's the only thing I can come up with, i think he mentioned that the metal ones seemed to do better with the heat. I just took it for granted and have used the metal ones myself and have had no reportable issue's either. They are pretty nice (well made), cost a few bucks more but seem worth it.

Interesting. I'll look into 'em!

 

[iamdub]

Drove thecopcar a while today. I've notice a few random times the cruise wouldn't engage. Today it would drop out of cruise intermitantly. Tapping the brakes reset it, and away we go again. I'm guessing it's time for a brake switch change.

Sounds like it. This is the typical mode of failure. If giving the brake pedal a sharp jab or lifting it with your foot behind it fixes it, it's pretty much guaranteed to be a funky switch.

 

[j91z28d1]

bypassed the ambient light sensor. Hooked up a 680 ohm and 10k ohm resistor to a relay harness. Triggered relay with trailer parking light fuse in fusebox. (the fused side, terminal furthest from cab) though im not sure if 18 gauge wire is enough to pop the stock 15A fuse, or if my wire would burn up with short) I might add a tap and put a smaller fuse in, though the wire is loomed up and in safe locations..

View attachment 401663
red wire (30 terminal) goes to the white wire in ambient light sensor (i de-pinned it and heat shrunk the wire on it in case it didnt work)
blue wire went to brown park lamp circuit (fusebox in my case)
all other wires are grounds, but two (87a and 87 terminals) with resistors soldered inline and a bunch of heat shrink to keep them from stressing the resistor leads.

no more dimming in the daytime, adjustable dimming at night.

UPDATE: One weird behavior.
When turning lights off, the dash display goes from nighttime dim, to off, then on daylight bright.
Does not cycle off when going from daytime to nighttime.
Not sure why, maybe the sudden change in voltage going from 10kohm resistance suddenly to 680ohm is too fast for the BCM to adjust?
That or some other electrical behavior I don't understand.. Any suggestions on how to wire a fix?

Reading up on something called a flyback diode.. something about voltage spikes when power to coil is cut, which would make sense why it happens turning lights off.
Ordered a relay with diode, but I'm not sure that's the issue.
also swapped my 85 and 86 (coil terminals) around. Sounds like conventionally 85 is -, and 86 is +.

I've not heard of this mod. what does it do?

 

[Doubeleive]

Never knew PPV had different wipers!?
I was thinking about hood mounted heated sprayers. Sucks when you have frozen wiper blades, and you can't get any spray on the windshield either.

There are a couple different designs of the arm's some of them on the earlier models are more angled and use a different connector instead a j hook, some do not lift up all the way because of a metal tab, the angled ones are pretty much used on the silverados and sierras
the main difference may be the mount one with groove's and one without, that part I haven't figured out yet

 

[mikez71]

I've not heard of this mod. what does it do?

All it does is bypass the light sensor, so when you are driving through a tunnel or under trees, the dash will not dim on you. That's it!
Unplugging the sensor will almost do the same thing, except your dash will be bright at night and the dimmer control won't work.

Looking like I need a diode on the relay. Here is a video that shows what happens..

I guess the BCM was sensing a big voltage spike from ground when switching the relay off. Hopefully I didn't hurt it!
Will test again when I get the new relay with diode. Will always add diodes to relays from now on!

 

[wjburken]

There are a couple different designs of the arm's some of them on the earlier models are more angled and use a different connector instead a j hook, some do not lift up all the way because of a metal tab, the angled ones are pretty much used on the silverados and sierras
the main difference may be the mount one with groove's and one without, that part I haven't figured out yet

I’d see if you can find a set off of a ‘13. Ours has the normal j-hook and lifts up all the way.

 

[Doubeleive]

I’d see if you can find a set off of a ‘13. Ours has the normal j-hook and lifts up all the way.

mine are j hook and lift up all the way, I was looking at maybe getting the more angled ones supposedly they do not lift in the wind and/or have more down force.

 

[iamdub]

There are a couple different designs of the arm's some of them on the earlier models are more angled and use a different connector instead a j hook, some do not lift up all the way because of a metal tab, the angled ones are pretty much used on the silverados and sierras
the main difference may be the mount one with groove's and one without, that part I haven't figured out yet

I’d see if you can find a set off of a ‘13. Ours has the normal j-hook and lifts up all the way.

The only change I ever knew of was when they went back to the traditional J-hook arms on (I think) '09+. I nabbed the arms off a newer one being parted out about a year ago to convert mine to the J-hook design. They included fairly fresh Bosch Icon blades. They lift up and stand straight out, but so did my old ones.

 

[j91z28d1]

All it does is bypass the light sensor, so when you are driving through a tunnel or under trees, the dash will not dim on you. That's it!
Unplugging the sensor will almost do the same thing, except your dash will be bright at night and the dimmer control won't work.

Looking like I need a diode on the relay. Here is a video that shows what happens..

I guess the BCM was sensing a big voltage spike from ground when switching the relay off. Hopefully I didn't hurt it!
Will test again when I get the new relay with diode. Will always add diodes to relays from now on!

interesting. not something that's ever bothered me. but cool you can do it.

 

[Doubeleive]

The only change I ever knew of was when they went back to the traditional J-hook arms on (I think) '09+. I nabbed the arms off a newer one being parted out about a year ago to convert mine to the J-hook design. They included fairly fresh Bosch Icon blades. They lift up and stand straight out, but so did my old ones.

the following in order are
1. the early design (angled)
2. the one on my 18 silverado
3. the current gmt900 version

 

[Doubeleive]

and looking at the photos I just realized the reason the silverado sprays so much better is because the sprayer is built into the cover that goes over the wiper linkage under the hood, it's not on the wiper arm.

 

[iamdub]

the following in order are
1. the early design (angled)
2. the one on my 18 silverado
3. the current gmt900 version
View attachment 401690
View attachment 401691
View attachment 401692

I had to go compare: I don't think I realized this when I installed 'em, but the end of my original wiper is mostly straight. The '09+ style, like in the third/bottom pic above, has that "Z"-shaped end. The main body part is the same between the two. That "Z"-ed offset makes the blade sit about 1.5" higher up the windshield when they're parked. I can't see any reason for this other than maybe for aerodynamics. Maybe the wiper being lower on the older style caused more wind noise?

 

[Doubeleive]

I had to go compare: I don't think I realized this when I installed 'em, but the end of my original wiper is mostly straight. The '09+ style, like in the third/bottom pic above, has that "Z"-shaped end. The main body part is the same between the two. That "Z"-ed offset makes the blade sit about 1.5" higher up the windshield when they're parked. I can't see any reason for this other than maybe for aerodynamics. Maybe the wiper being lower on the older style caused more wind noise?

dunno

 

[swathdiver]

the following in order are
1. the early design (angled)
2. the one on my 18 silverado
3. the current gmt900 version
View attachment 401690
View attachment 401691
View attachment 401692

My pickups have the top one and use a beam blade and the Yukon has the bottom one of course with the J-Hook attachment.

I was wondering if I could swap to their style since our windshields are likely the same? This would simplify parts ordering too!

 

[Doubeleive]

My pickups have the top one and use a beam blade and the Yukon has the bottom one of course with the J-Hook attachment.

I was wondering if I could swap to their style since our windshields are likely the same? This would simplify parts ordering too!

ya when I checked the crossover it shows the angled one fits 07-13 pickups and some years of the tahoe's
dorman sells one that is for the police package which crosses over to the same part number.
the angled ones are on the ppv's you can see them sticking up higher than regular arms
I use the trico force blades which are high speed rated but thought it might be even more beneficial to use the angled arms but not sure if I like them sticking up like they do or if the mount is compatible or not.
if I can find some in the junkyard I might see if they fit or what they look like on a yukon, new ones are $40-60 each
don't really want to spend a $100 just see if I like them not lol, plus it's done raining here now so no rush.

 

[Sparksalot]

ya when I checked the crossover it shows the angled one fits 07-13 pickups and some years of the tahoe's
dorman sells one that is for the police package which crosses over to the same part number.
the angled ones are on the ppv's you can see them sticking up higher than regular arms
I use the trico force blades which are high speed rated but thought it might be even more beneficial to use the angled arms but not sure if I like them sticking up like they do or if the mount is compatible or not.
if I can find some in the junkyard I might see if they fit or what they look like on a yukon, new ones are $40-60 each
don't really want to spend a $100 just see if I like them not lol, plus it's done raining here now so no rush.

So, you’re saying the wiper arms on thecopcar aren’t standard gmt900 fare?

 

[89Suburban]

Replaced the valve cover gaskets, and cleaned up the schmoo from the valve covers.

View attachment 401525
View attachment 401526

Couldn't even start installing this clamp, because the ground strap bolt is King-Konged into the head. I guess I'll try to go up from below, but will have to remove the front drive-shaft.
View attachment 401527

I just noticed the 6.2 stamped under one of the valve covers. Is that because the 5.3 and 6.2 share the same heads?

Also, the Fel-Pro gasket set came with an extra gasket, and I have no idea where it is supposed to go. Looks like this:
View attachment 401528

Any clue?

You can't post up those nice and clean and shiny "after" valve cover pics, without some "before" pics.

Sucks about the head bolt, I was really hoping you would come out victorious.

 

[Charlie207]

You can't post up those nice and clean and shiny "after" valve cover pics, without some "before" pics.

Sucks about the head bolt, I was really hoping you would come out victorious.

Here you go:

I only had a pic of one of the valve covers pre-wipe. The other one pretty was similar.

As for the ground strap bolt, I ordered a set of swivel-head ratcheting wrenches, and maybe that will help.