4x4 help please!
#1
4x4 help please!
I have service 4x4 lit and no 4 wheel drive . The 2 hi light is on solid . If i push 4 hi or 4 low they blink then it goes back to 2 hi. I've been reading up and dont want to waste anyones time here but I ran into a problem while trouble shooting .. The switch has been re-soldered it had some cracked joints. The tccm has been removed cleaned and corrosion removed now it clicks when i push the buttons ...now the problem .. After pulling the battery/tray and restarting truck to check the acuator ..as soon as it pulls in with the battery out of the truck the truck stalls... any ideas ? Also with the battery back in and pushing 4hi / lo a buzzing sound coming from encoder motor ( which I think is the 4 wheel drive problem) but why the stall without battery ?? Ive seen others do it with no problems .. bad ground ?
#2
I have service 4x4 lit and no 4 wheel drive . The 2 hi light is on solid . If i push 4 hi or 4 low they blink then it goes back to 2 hi. I've been reading up and dont want to waste anyones time here but I ran into a problem while trouble shooting .. The switch has been re-soldered it had some cracked joints. The tccm has been removed cleaned and corrosion removed now it clicks when i push the buttons ...now the problem .. After pulling the battery/tray and restarting truck to check the acuator ..as soon as it pulls in with the battery out of the truck the truck stalls... any ideas ? Also with the battery back in and pushing 4hi / lo a buzzing sound coming from encoder motor ( which I think is the 4 wheel drive problem) but why the stall without battery ?? Ive seen others do it with no problems .. bad ground ?
Check to make sure the transfer case is not stuck by removing the encoder and clicking through the selections using a wrench on the shaft. If not stuck, then replace encoder motor. If still won't work replace TCCM. From your description, it's not the controls.
ps Summit Racing can get you anything and will price match anything on the Internet. Plus 1-2 day shipping and no tax. They also have very liberal and easy return policies. So does Amazon. So shop around. Cardone parts worked fine for me.
But if you feel need to know for sure before replacing any parts, then a Tech 2 and a dealership is in order unless you go through the wiring schematics, understand the operation, and devise your own testing. Sometimes paying someone to do diagnostics cost more than all the parts possibilities when doing things yourself.
Last edited by LesMyer; 02-07-2017 at 11:56 AM.
#3
That makes sense .. The reason I asked on here was because I've seen it done and the engine doesn't die like mine did even with a bad encoder motor. I will pull the encoder this weekend and see if it cycles through .. I appreciate the response .
#4
Just take it off and make sure the TC can be clicked through it's range using a wrench. If the TC can and the TCCM clicks, then start by replacing the encoder motor as I described.
Now, if you want to disconnect the electrical connectors from the encoder motor (leaving it on the transfer case) and see if the engine still dies when you select 4WD, that could possibly tell you if the encoder motor is pulling too much current. But to me that already seems fairly obvious. Only thing I don't know is if the TCCM will also be junk from excessive current through it or from ineffective repairs (soldering on it).
good luck and best wishes for a successful repair.
Last edited by LesMyer; 02-09-2017 at 07:51 AM.
#5
The 4 wheel drive selection switch is what was soldered .. The joints were cracked and the lights would randomly go out and come back on .. I meant to use a wrench and see if the TC cycles not the encoder. I started with the in dash switch, TCCM, vacuum switch on the firewall, actuator now down to the bottom . I haven't changed the vacuum switch on the TC or the encoder so hopefully it's one or the other .. I'll let you know .
This caused my lights to randomly go on and off .. Not sure how this picture will upload but the 4 solder joints at the top in a row are all cracked all the way around. This is what was soldered .
This caused my lights to randomly go on and off .. Not sure how this picture will upload but the 4 solder joints at the top in a row are all cracked all the way around. This is what was soldered .
#6
Yeah I got it wrong. You did say switch was soldered and TCCM terms were cleaned.
If you want to check your switch operation with a digital multimeter, that can easily be done. Note that the indicator lights in the display are powered by voltage feeding back from the TCCM, so flickering lights there could also be from a TCCM or wiring or corrosion/connector problem.
https://blazerforum.com/forum/tech-a...rmation-41198/
FYI - vacuum switch is on the firewall for 4-button Auto 4WD. Vacuum switch is on the transfer case for 3-button 4WD. Not both places on any system. Hopefully save you some looking. Sounds like you have a 4-button NV236 if you have checked a vacuum switch on the firewall.
If you want to check your switch operation with a digital multimeter, that can easily be done. Note that the indicator lights in the display are powered by voltage feeding back from the TCCM, so flickering lights there could also be from a TCCM or wiring or corrosion/connector problem.
https://blazerforum.com/forum/tech-a...rmation-41198/
FYI - vacuum switch is on the firewall for 4-button Auto 4WD. Vacuum switch is on the transfer case for 3-button 4WD. Not both places on any system. Hopefully save you some looking. Sounds like you have a 4-button NV236 if you have checked a vacuum switch on the firewall.
Last edited by LesMyer; 02-10-2017 at 07:35 AM.
#8
Ok ..what would make the actuator get pulled in ..almost all the way then it just releases like it lost all vacuum .. Vacuum switch? .. I squeeze the actuator in by hand with truck off and I hear a hiss.. I traced the sound back to the vacuum switch on the firewall . There is a tiny hole in the top of this thing that air comes out when I squeeze the actuator .. is it bad ?
#9
Ok ..what would make the actuator get pulled in ..almost all the way then it just releases like it lost all vacuum .. Vacuum switch? .. I squeeze the actuator in by hand with truck off and I hear a hiss.. I traced the sound back to the vacuum switch on the firewall . There is a tiny hole in the top of this thing that air comes out when I squeeze the actuator .. is it bad ?