Revised transfercase switch *READ THIS THREAD!

doughboy5499 · Post by **doughboy5499** » Mon Feb 26, 2007 5:40 am

HenryJ wrote:

The new switch is part number 89059420 and has a blue inspection paint mark.
The old switch is part number 15664811 and has a green inspection paint mark. (see picture below)

Had the right thread, just had to scroll up.

rickscrewcab · Post by **rickscrewcab** » Mon Jul 23, 2007 3:36 am

yup...I just noticed that mine is hissing now. Glad I bought the extended warranty. This may explain why the a/c temp isn't as cold as it used to be.

green02crew · Post by **green02crew** » Sat Nov 17, 2007 7:39 pm

My truck is passed warranty and has not had this part replaced. The part is at a local Autozone for 15$. Is that part just as good or should I go directly to the dealer?

F9K9 · Post by **F9K9** » Sun Nov 18, 2007 4:11 am

Dealer or GMPartsDirect.com

green02crew · Post by **green02crew** » Wed Nov 21, 2007 8:11 pm

I just replaced my switch, the old one had failed and there was some fluid in the lines that I could see. Everything is working just fine as it should with no malfunctions including no air being let by when the air is set to off. Is it possible that something could go wrong later due to fluid being left in the lines or am I safe since I changed the switch before enough fluid got into the lines causing something to go seriously wrong?

Post by **HenryJ** » Wed Nov 21, 2007 8:24 pm

Time will tell. You have rolled the dice.

24digger · Post by **24digger** » Mon Dec 31, 2007 1:34 pm

What year of trucks do these bad switches include?

For the past month my 95Zr2 has been hissing when I put it in heat only.

Finally got around to look at it today and it had what looked to be trans fluid inside of switch where it turned to make the selection. Or it may have been a lubricant couldn't really tell. Tried to smell it, but really didn't have any.

I did manage to get it to stop hissing a little.

Post by **HenryJ** » Mon Dec 31, 2007 1:37 pm

I really don't know. My 1986 S-10 4x4 has not had a problem. The heater control differs as does the vacuum system. It could go back quite a way. I would say it is safe to say that the second gen trucks seem to have more problems.

24digger · Post by **24digger** » Mon Dec 31, 2007 3:24 pm

Well I had problem with 4wd coming out and going back into 2hi a month or so ago.

Much like one of the other posts here where it sounded like a buzz saw. I had taken it out of 4wd and went down the road and everything was fine until I started slowing down for an intersection. Then it sounded like the truck was coming apart. Did this twice and has been fine since.

I think it probably hadn't fully came out of 4wd yet and was stuck inbetween.

I don't know if it is related or not.

I think maybe my switch selector is bad since it only hisses on one selection.

rickscrewcab · Post by **rickscrewcab** » Fri Jan 25, 2008 3:01 pm

Had my CC in the shop for a few adjustments and repairs this week. Told them about the hissing when my selector switch is in vent mode. Gave them a copy of the bulletin too. Sure enough, the switch was leaking and I had contamination up to HVAC controller. They replaced the switch, controller and cleaned all the lines at no charge. Got my new tailgate support cables at N/C too.
And talk about perfect timing...after they finished my CC and had it out for a test drive, my "Service engine soon" light came on. Found my termostat sticking and Oxygen sensor bad. More N/C!!!

williamcstonejr · Post by **williamcstonejr** » Thu Feb 21, 2008 3:36 pm

After all of my other 4x4 issues I decided to stop avoiding this situation in need of attention. Brule was right, ten minutes tops and this is a stock CC no lift. I did have a small amount of tranny fluid on the top right vacuum port. Everything went smooth but it helps to have a swivel ratchet. Although my final alignment was 180 off from the original switch. Did I mention the part $52.85 from my dealer, they refused to lower the price. GM direct would be a better option if you have the time. I just ignored this way to long and felt I had to do it ASAP and paid the extra $18.00 for the comfort of knowing I wasnt going to spend a lot more further down the line.

Other than a floor jack and jack stands these are the tools I needed for the job.

roadrunner · Post by **roadrunner** » Mon Apr 28, 2008 8:35 pm

Stopped at the local dealer today going to pick up a switch #89059420 (blue stripe). They informed me it has now been superceded by the old #15664811 (green stripe).

Said they'd have to order it as they didn't have it on hand. When I checked a couple months ago they had the blue stripe newer number on hand. Told me they probably sent it back as "old stock".

I told them to forget it. I will find it elsewhere. Sounds like they've got their supercessions mixed up to me.

JaVeRo · Post by **JaVeRo** » Tue Apr 29, 2008 10:33 pm

I found something I consider to be a design flaw last weekend. One of the three ports connecting to the switch is a vent that is tied to the transmission dipstick. In that line is a Y connector and the vent for the transfer case is also connected to it. It saved them about 4 feet of vacuum hose.

I could see it happening real easily, bouncing thru a mud hole and sloshing some fluid from the transfer case into the vent line, then you take it out of 4wd and the fluid gets sucked up toward the motor. It wouldn't be a problem with the switch, just two lines connected together that (in my opinion) should not be.

I will get pics this weekend before I replace it with two separate vent lines.

James

roadrunner · Post by **roadrunner** » Wed Apr 30, 2008 6:10 pm

JaVeRo wrote:I could see it happening real easily, bouncing thru a mud hole and sloshing some fluid from the transfer case into the vent line, then you take it out of 4wd and the fluid gets sucked up toward the motor.

I was just under mine finishing skid plate installs today and replacing tc vac. switch (found one at another dealer). Saw what you're talking about. Not saying what you're talking about couldn't happen but it'd take one h**l of a bump to do that. I have not had one of the 233 t-cases from a CC apart but the older models all had a sort of splash-guard in them to prevent what you're expressing fear of.
As to the engineers, one once told me they'll fight hard to save two cents on the cost of anything on a vehicle. Simple math $.02X how many million vehicles? I don't like it either but that's the way they operate.

Jongo88 · Post by **Jongo88** » Tue Feb 10, 2009 6:51 pm

After reading this I'm worred to death. I just bought my cc 2 weeks ago and now first thing tomorrow. I'm going to pull it out and look to see what color the stripe is. My cc has 77,000 miles on it now.

roadrunner · Post by **roadrunner** » Tue Feb 10, 2009 6:59 pm

Save yourself some aggravation and go get a new blue stripe switch part number as noted above and replace it while you're checking it. At that low of miles it's not likely it's been replaced yet. JMO

F9K9 · Post by **F9K9** » Tue Feb 10, 2009 7:05 pm

Jongo8 wrote:After reading this I'm worried to death............

Don't sweat the small stuff. If, you have 77K and everything is working then you have a little time to play with. The time to worry is when you find ATF in your ashtray.

If, you find the lines moist when you check them then don't panic then either.

I found mine just with traces of ATF in them over 2 years ago and all is still working well after the switch replacement.

Jongo88 · Post by **Jongo88** » Wed Feb 11, 2009 10:25 am

Well I pulled off the hoses and they are dry. I can't see what color the stripe is so I'm just going to buy a new one. I'll have to give the wife about 2 weeks to let me spend more money. She said I got the truck that should be good. But I have a lot I want to do to it. So It's not leaking so I going to let it go just for now.

green02crew · Post by **green02crew** » Wed Feb 11, 2009 2:17 pm

Don't let it go long, replacement is cheap and easy compared to issues that may come up.

Post by **HenryJ** » Wed Feb 11, 2009 2:45 pm

As far as I know the switch in my 1986 is original and does not have problems. The crew cabs did indeed have a problem with them , I am not sure if it applies to earlier s-series, or the last couple years of the crew cab.

jstein · Post by **jstein** » Wed Feb 11, 2009 2:55 pm

I am so glad I found this forum. I was ready to tear my entire dash apart. Has anyone had any luck buying the part from an Autozone type store? I know Green02crew asked this question above. My dealer wants to soak me for $44. I found one at a local parts store for $19.95. Any advice?

Post by **HenryJ** » Wed Feb 11, 2009 3:01 pm

That is about the same price as the dealer IIRC.

Jongo88 · Post by **Jongo88** » Tue Feb 24, 2009 9:39 am

I changed mine out today. Very easy to change. Took like 10 min. I cleaned out the vacuum lines. They had oil in them. I pulled out the AC control and it is clean. So I think I got it in time. The ripoff dealer charged me $56.00 for the switch and $6.56 for the O-ring. What a joke. I had to get them as I had the truck up on the ramps and the old switch out. I'm just glad I got it done.

jstein · Post by **jstein** » Tue Feb 24, 2009 2:58 pm

I replaced my switch the other day and my system is still not working. I did find ATF in the lines and I cleaned them with q-tips and alcohol. When I tried to reconnect the vacuum hose I found that I could not get it on all the way. I struggled with it for about 20 min until I finally gave up. Has anyone else had this problem? It seems the hose engages about 75% but will not budge that last bit. I compared the 2 switches and they are identical. Any thoughts?

Jongo88 · Post by **Jongo88** » Tue Feb 24, 2009 3:31 pm

do you have the pin lined up with the plug? If not it won't go on all the way because the pin is holding it up.

jstein · Post by **jstein** » Tue Feb 24, 2009 6:18 pm

I did check for this and the pin is lined up correctly. I can't understand why it will not seat properly. After the new switch was installed and torqued I noticed that it sat maybe 90 degrees from where the original was (the switches were identical except for this minor detail.) I thought that maybe there was too much strain on the vacuum lines pulling back on the plug but it seemed to have sufficient slack.

jedthrocornpone · Post by **jedthrocornpone** » Mon Apr 06, 2009 3:57 pm

just wanted to leave a note about $$$ her in Oregon

GMPartsDirect.com 39.51 shipped
loacl GMC Dealer 44.70
Loacl Chevy 50.18
somewhat local GM 40.80

looks like a road trip is in order maybe I should take the wifes rig? I'm spooked about this too I have no hissing and my 4wd works its just I can't seem to choose my vents after I have been in 4wd

they come back and work fine after a while.

fingers crossed for dry lines

jeggers · Post by **jeggers** » Tue Jan 24, 2012 9:32 am

I have a bad switch in my S-10, I have ATF in the lines I have already replaced the front axle acuator and the acuator behing the glove box. I am going to look into a 2wd parts truck to replace the rest of the hvac system. I picked up a switch from the auto parts store. I need to drop the transfer case to replace the seel between it and the trans. I plan on replacing it then. are the hoses (3) from the transfer case avalable from the dealer? The trans leak and this transfer case switch is only 2 of the issues with the truck. It is popping the p0300 code, Thanks to Hj I checked the previous owners tune up job and found that the front screw holding down the cap was stripped out. This truck has beem missing for about 12k miles. The motor was replaced with a juck yard motor 12k ago this less then 30k on the new motor. I should not have needed the tune up. My gues is that it was the vacuum leaks and the atf feeding into the motor that was causing the missfires. Now I need a ditributor, cap , rotor and new plugs. I nicked one of the plug wires so got to chang them to. any good ignition combo kits out there that will boost the performance? any other issues this switch failure can cause? Thanks

jeggers · Post by **jeggers** » Sat Jan 28, 2012 9:45 am

MCbowhunter · Post by **MCbowhunter** » Sat Apr 26, 2014 7:27 pm

Gents I realize this is an old thread, but I just found it last night

while looking for any clues as to why my truck would not go into 4hi. Just recently my truck started to not blow through the vents on the floor. Anyhow I went to the dealership today to buy the Transfer case vacuum switch. I bought it at cheap price......$60

maybe inflation?
However now I know that I will have the peace of mind in knowing that it is the good one.
I have not gotten under the truck yet to see if there is any fluid in my lines. We shall see soon though, it will be here Monday. Just wanted to give any body that hasn't gotten the switch yet a heads up.

roadrunner · Post by **roadrunner** » Sun Apr 27, 2014 9:19 am

MCbowhunter wrote:Gents I realize this is an old thread, but I just found it last night while looking for any clues as to why my truck would not go into 4hi. Just recently my truck started to not blow through the vents on the floor. Anyhow I went to the dealership today to buy the Transfer case vacuum switch. I bought it at cheap price......$60 maybe inflation?
However now I know that I will have the peace of mind in knowing that it is the good one.
I have not gotten under the truck yet to see if there is any fluid in my lines. We shall see soon though, it will be here Monday. Just wanted to give any body that hasn't gotten the switch yet a heads up.

If you have no fluid in the lines the next place is to start checking ALL vacuum lines including those by the master cylinder and those to the vacuum pod that engages the 4wd under the battery. Especially since you've lost heater/ac vacuum door control.

Hartleybl · Post by **Hartleybl** » Tue Apr 29, 2014 7:22 pm

since i have done the bravada axle swap do they not make a plug... like a diff drain plug to put in place of the vac switch... i plugged off the vac line next to the drivers fender but i'd like to just do away with it all together thanks

Horsehammerr · Post by **Horsehammerr** » Mon Jun 16, 2014 2:45 pm

Just purchased P.# 89059420 switch at GMPartsdirect for $29.47 + $10.97 S&H = $40.44

Horsehammerr · Post by **Horsehammerr** » Thu Jun 26, 2014 3:11 pm

Horsehammerr wrote:Just purchased P.# 89059420 switch at GMPartsdirect for $29.47 + $10.97 S&H = $40.44

Got my switch today, only took 10 days :rah:

Jack it up and put stands under and took a look, seems maybe easier access with front drive shaft removed or just jack it up higher.

rlrnr53 · Post by **rlrnr53** » Fri Jun 27, 2014 7:08 pm

It's not easy to get to, the driveshaft might be the easiest.

pidjones · Post by **pidjones** » Sat Sep 02, 2017 1:27 pm

Was really lucky that our switch is still fine..... but..... only ~ 6" of the three lines attached - the rest eaten off by chipmunks. I plan to wire-tie some Black Cat bait blocks around the truck to give them a treat with a belly ache. BTW, all lines (over 30 ft total) replaced and 4wd works great as well as HVAC and no codes anymore!

S-10CREWCAB.NET

Revised transfercase switch *READ THIS THREAD!

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Re: Revised transfercase switch *READ THIS THREAD!

Re: Revised transfercase switch *READ THIS THREAD!

Re: Revised transfercase switch *READ THIS THREAD!

Re: Revised transfercase switch *READ THIS THREAD!

Re: Revised transfercase switch *READ THIS THREAD!

Re: Revised transfercase switch *READ THIS THREAD!

Re: Revised transfercase switch *READ THIS THREAD!

Re: Revised transfercase switch *READ THIS THREAD!

Re: Revised transfercase switch *READ THIS THREAD!