How to: 4x4 Troubleshooting guide

[Four0Sport]

deffinetly an invaluable resource.. i wish we were getting slammed with snow. the temp is actually rising, its currently 55 in WV.

 

[turboranger91]

this definitely clears things up as far as why auto hubs need to be converted.

 

[tyler_h]

i wanted to thank i almost went out an bought a new motor to switch the 4wd extremly useful A+

 

[rockclimber]

Sorry for posting here. I know it is meant to be a thread to consolidate ideas not ask questions but my questions hasn't received much attention elsewhere. I will try to make it as brief as possible.

2 years ago i fixed the 4wd shift motor by replacing the little rubber bushing, it has worked great until the other day. Now when the button is pushed on the dash nothing happens. No light and no clicking from the shift module back by the jack. I have disconnected the shift module and pushed the test button. The red led flashed 4 times. Reassembled everything and pushed the 4wd button on the dash....NO CLICKING FROM THE MODULE.

To simplify i guess it boils down to two questions.

1) can the shift motor be the problem even if the shift module isn't clicking and the button isn't lighting up? it seems to me that without the shift module clicking the shift motor wouldn't have the opportunity to turn and get lost (i.e. the stop bushing in the shift motor that i HAVE replaced)

2) how can i test the 4wd switch? as i said there are 8 totoal connections back there. i'm buying a multi meter but even with that i don't know which connections do what. when i push the button the shift module doesn't seem to be activated.....no clicking.

Post to start this thread says......

"If the relays make noise it indicates the 4x4 module has received input from the dash button and the problem lies in either the 4x4 computer or the shift motor."

so it seems that my module isn't receiving input from the dash button??? should i just buy a new button assembly or are there other things i need to check first.

if the shift module were clicking i would say the bushing i installed in the shift motor had failed.

Any suggestions?
Words of wisdom?
A good joke?
????
aaaaaaarrrrrrgggghhh!
RC

 

[Verno]

Sorry for posting here. I know it is meant to be a thread to consolidate ideas not ask questions but my questions hasn't received much attention elsewhere. I will try to make it as brief as possible.

2 years ago i fixed the 4wd shift motor by replacing the little rubber bushing, it has worked great until the other day. Now when the button is pushed on the dash nothing happens. No light and no clicking from the shift module back by the jack. I have disconnected the shift module and pushed the test button. The red led flashed 4 times. Reassembled everything and pushed the 4wd button on the dash....NO CLICKING FROM THE MODULE.

To simplify i guess it boils down to two questions.

1) can the shift motor be the problem even if the shift module isn't clicking and the button isn't lighting up? it seems to me that without the shift module clicking the shift motor wouldn't have the opportunity to turn and get lost (i.e. the stop bushing in the shift motor that i HAVE replaced)

2) how can i test the 4wd switch? as i said there are 8 totoal connections back there. i'm buying a multi meter but even with that i don't know which connections do what. when i push the button the shift module doesn't seem to be activated.....no clicking.

Post to start this thread says......

"If the relays make noise it indicates the 4x4 module has received input from the dash button and the problem lies in either the 4x4 computer or the shift motor."

so it seems that my module isn't receiving input from the dash button??? should i just buy a new button assembly or are there other things i need to check first.

if the shift module were clicking i would say the bushing i installed in the shift motor had failed.

Any suggestions?
Words of wisdom?
A good joke?
????
aaaaaaarrrrrrgggghhh!
RC

RC, My first thought, coming from an electrical background, would be you are not telling the module to change. If you have a Haynes manual, it will tell you wire color to check for voltage (at module) once switch on dash is engaged.

 

[rockclimber]

Just trying to keep this alive so maybe someone will see it and have an idea. I tried a new push button switch today with no luck. So here is what has been done....

1) i replaced the rubber stop in the shift motor approx 2 years ago and it worked fine up until now.

2) checked the shift module. With the wires unplugged the red led blinks 4 times when the white button is pressed.

3) when i press the 4wd button NOTHING happens. The shift module does NOT click......

it seems to me that the shift module isn't getting input from the dash button. I have a haynes manual and am trying to figure out the wiring diagrams without much luck. Combined with the fact that i bought a digital multimeter that has almost no instructions and things aren't going very well.

ideas?

RC

 

[rockclimber]

Does anyone know where to find the wiring diagram for the 4wd stuff?

With the engine running i tested the wire plug that plugs into the back of the 4wd dash switch. It consists of two vertical columns of 4 wires each. Testing them as pairs (left and right) i got some odd numbers. The bottom 3 pairs were all right around 12 volts but the top pair (top right and top left) came out at 4-5 volts....? Does this mean there is a short somewhere? I can't even follow the wires let alone see a short....?

Does anyone know if this is how it is supposed to be? Can anyone test the wire plug behind their 4wd switch? (if you are ever in town i promise i'll buy you a beer for your troubles)

I'm a very amateur mechanic at the best of times but electrical stuff i have almost no experience in. I can't find the wiring diagram for the 4wd components in the haynes manual and even if i can from the looks of the other diagrams i may be SOL.....

RC

 

[DeRocha]

Just trying to keep this alive so maybe someone will see it and have an idea. I tried a new push button switch today with no luck. ...

i bought a digital multimeter that has almost no instructions and things aren't going very well.

ideas?

RC

Was the new switch really new, or from a salvage yard? Often times salvage yard 4x4 switches can be in poor shape because the previous owner pushed the crap out of the button in a futile attempt at getting 4x4 working.

Anyway you need to use your meter and confirm the 4x4 wires are receiving voltage. The (switch) wires we are looking for are W/LB and DB. The W/LB wire contains the carrier voltage from the 4x4 computer which will be sent back to the 4x4 computer via the DB wire.

To use your meter:
Take your meter and set it for DC voltage (if it has individual settings then set it 15-20v range). Pop the hood and connect/hold the black (neg) side to some ground bolt near the battery. Touch the red/pos side to the + side of the battery.. the meter should read ~12v. You can then get back to the cabin and connect the neg wire of the meter to a known good ground and use the red wire to probe/test the W/LB and DB wires.. Note the 4x4 button is a momentary contact (so its voltage will only bee seen for a few secs after the button is pressed)

See videos like

 

[DeRocha]

Does anyone know where to find the wiring diagram for the 4wd stuff?

With the engine running i tested the wire plug that plugs into the back of the 4wd dash switch. It consists of two vertical columns of 4 wires each. Testing them as pairs (left and right) i got some odd numbers.

RC

I sent you the 4x4 wiring diagram
As for testing the neg/black lead on the meter must always go to a known ground.. You can use the black wire on the switch, or any ground bolt in the cabin. After that you can probe the wires with the red lead to determine voltages... As mentioned the 4x4 buttons are momentary switches and will only transmit voltage for a few secs.

 

[rockclimber]

DeRocha,
Thanks so much for the help. I was tooling the net trying to figure out the meter some more. Didn't realize to put the black on a ground and test individual wires with the red....learn something new everyday!

When you say "4x4 comuputer" do you mean the shift module (located in the back near the jack)? I've only heard it called the shift module....If the red led blinks 4 times is it safe to assume that everything is ok there?

Also what do you mean by w/LB and DB? Is that somehow refering to the colors of the wires?

Thanks also for the wiring diagram. I'm off to look at it (which may answer my w/lb and db question.

Regarding the switch. Yes it was from a junk yard. However i tried two different ones....that would mean i've tried 3 junk switches. Is there a way to test the switch with the multi meter? From what i understand if i set the meter to ohms it should measure if the circuit is completed when the switch is closed? Would i need to figure out what pins the w/lb and db wires connect to then put my probes on those pins and push the button?

Thanks so much to everyone here. This site has saved my bacon once already....hopefully i can figure this one out also.
thanks
RC

 

[rockclimber]

W/LB = white/light blue ?
DB = dark blue?

I was out and took a look the diagram helped understand somewhat. So i put the black probe on a good ground and the red on the white/light blue wire....5volts. I put the black probe on a good ground and the red on the dark blue wire....0volts. What should they test at? I'm guessing at least one of them should be 12?

I'm off to check the BK/W which i'm assuming is going to be black and white at the shift module. It looks like that is where the shift module gets its juice from the battery???

 

[rockclimber]

So the search continues......
For those who want more info on the problem, please see my posts above.

In testing the wires for the 4wd switch i found that the W/LB wire is only at 4-5 volts. I next went back to the shift module (in the back near the jack). The 4wd wiring diagram shows that the power comes in on a black and white wire (BK/W). I found a wire plug connection where a green and yellow wire connected to a black and white wire on the shift module. The green and yellow wire tested at 12 volts so i'm assuming the black and white wire that it connects to is taking 12 volts to the shift module.

I was hoping to test the white and light blue (W/LB) that comes out of the shift module and goes to the 4wd switch. Unfortunately the connection from the module looks to be some kind of computer circuit board that the wires in the wire plug connect to so i was unable to test the W/LB output from the shift module.

Questions
1) The diagram that i have does not indicate how many volts each wire is supposed to be. Is it safe to assume that the hot wires should be 12 volts? (i.e. the W/LB at the switch should be 12 not 4-5volts.)

2) If that is the case how can i test the W/LB going out of the shift module?

3) Why would the W/LB be 4-5 volts at the switch if the module is receiving 12 volts?

4) How can i fix this? The diagram shows that the switch should receive current on the w/lb wire and send it back to the shift module on the DB wire. If it should be 12 volts, is there a way to re-wire it so that the switch receives 12 volts and transmits 12 volts when the switch is pushed?

I'm new to the whole wiring aspect so diagrams or explanations are greatly appreciated.
Thanks!
RC

 

[FRED 94]

Not going into 4low

I replaced the busing and it will go into 4H but when I push the 4L it puts it back into 2H. What could be causing this problem?:scratch:

 

[DeRocha]

So the search continues......

I was hoping to test the white and light blue (W/LB) that comes out of the shift module and goes to the 4wd switch. Unfortunately the connection from the module looks to be some kind of computer circuit board that the wires in the wire plug connect to so i was unable to test the W/LB output from the shift module. RC

The tip of the metal probe on your multi-meter is designed to penetrate the outer insulation on wires. Yes it makes a tiny pin hole, but it allows you to test the wire(s) when you have no access to the terminals.

As such you want to test the wire without pressing the 4x4, then again when pressing 4x4..