low range and 4x4 light on

[bakerc167]

My low range an 4x4 light are both on an my 4wd does not work. Ive checked fuses an unplugged transfer care plug an pluged it back in. its the electric turn knob, any ideas out there?

 

[907DAVE]

Do the lights go out when the t-case shift motor is unplugged?

 

[bakerc167]

yes they go out when its unplugged

 

[907DAVE]

Does your overdrive cancel switch work?

 

[bakerc167]

no it hasnt worked for a little while now.

 

[907DAVE]

Check fuse 19 (10 amp) in the fuse panel under the hood.

 

[bakerc167]

I checked 17 i believe it was this morning but ill check that tomorrow

 

[JLDickmon]

"4x4 does not work" is a broad statement..
does the front driveshaft turn?
is there vacuum getting to the front hub lockouts?

 

[Zmann]

the 4x4 lights aka PCM don't know if the hubs work they just assume they do


he has a transfer case actuator issue or fuse like mentioned

do you here the electric motor when you shift ? try it with the truck off you should here a electrical mechanical noise

 

[4 Wings]

Sounds like the T-case shift motor could be bad. Re-check your in-cab and underhood fuses. If all are good, put it in 4x4 and check for power at the harness plug to the motor. If the motor is getting power, it's probably shot. We have them if you need one.

If the OD cancel switch won't light and fuses are all ok, remove the plastic steering column cover. Check the wiring to the OD cancel switch for an open circuit. Sometimes the small wires to the switch get pinched, cut, or frayed in the upper column area. The OD cancel button is a contact switch, the light is a LED energized by the button. Occasionally they go bad. We have good used shift lever assemblies with complete switches if needed. Also new replacement ends for the OD cancel switch button.

Hope this helps. :thumbup:

 

[revolvingsteel]

Subscribed, I'm having similar issues.

 

[JLDickmon]

the 4x4 lights aka PCM don't know if the hubs work they just assume they do


he has a transfer case actuator issue or fuse like mentioned

do you here the electric motor when you shift ? try it with the truck off you should here a electrical mechanical noise

I remain unconvinced of such. Just sayin'..
When mine was acting up last year, one of the things I found out was the 4x and Low indicators are tripped by the encoder motor on the t-case. It's got four switches inside it. The switches send logic signals back to the GEM and PCM, which in turn illuminate the lights.

The statement

PCM don't know if the hubs work they just assume they do

is true, but we can't assume they work. He could have everything else operating normally, if either hub is not engaging, the front differential will do it's job, and "4x4 will not work"

I had this problem just a couple weeks ago.. one Warn wouldn't stay engaged. Weak spring. Had it replaced under warranty, boom. No problem

So, all that being said...
The 4x light comes on when commanded.

Does it go off when 2wd is selected?

Are the hubs getting vacuum to them?
If you turn them manually to "Lock" and make a tight turn, does the truck "bunny hop?"

 

[bakerc167]

Fuses are all good, i cant hear anything when i turn the switch. but now the lights are off an 4x4 still does not work. when the lights where on the where always on but now they are off.

 

[bakerc167]

Sounds like the T-case shift motor could be bad. Re-check your in-cab and underhood fuses. If all are good, put it in 4x4 and check for power at the harness plug to the motor. If the motor is getting power, it's probably shot. We have them if you need one.

If the OD cancel switch won't light and fuses are all ok, remove the plastic steering column cover. Check the wiring to the OD cancel switch for an open circuit. Sometimes the small wires to the switch get pinched, cut, or frayed in the upper column area. The OD cancel button is a contact switch, the light is a LED energized by the button. Occasionally they go bad. We have good used shift lever assemblies with complete switches if needed. Also new replacement ends for the OD cancel switch button.

Hope this helps.

The OD wires where broke, my buddy has another shift lever he is bringing me this weekend, I havent checked to see if power is making it to t case or not yet. but i believe it is because when i would unplug the wires the lights would go out.

 

[bakerc167]

Are the hubs getting vacuum to them?
If you turn them manually to "Lock" and make a tight turn, does the truck "bunny hop?"

truck came with warn hubs i dont see any vaccum lines

 

[4 Wings]

The OD wires where broke, my buddy has another shift lever he is bringing me this weekend, I havent checked to see if power is making it to t case or not yet. but i believe it is because when i would unplug the wires the lights would go out.

["insert I was right because I'm a professional that does this everyday to earn a living-- icon here"] LOL LOL



:rockon: :rockon:

 

[907DAVE]

Yeah, but I said it first! Well, thats what I was getting to by asking if the fuse 19 was blown.

 

[4 Wings]

Yeah, but I said it first! Well, thats what I was getting to by asking if the fuse 19 was blown.

:toast:

 

[Zmann]

The statement is true, but we can't assume they work. He could have everything else operating normally, if either hub is not engaging, the front differential will do it's job, and "4x4 will not work"

For anyone else researching this issue
We don't have to assume anything on the vacuum hub system, the PCM does that for us and that has nothing to do with his 4x4 - 4 low lighting transfer case issue that was the whole question on this post
so it doesn't even play into His question ,, apparently He does not even have the ESOF Hubs anymore anyway

My low range an 4x4 light are both on an my 4wd does not work

but would play into a non working 4x4 system

 

[JLDickmon]

I look at it this way.. making my living fixing this stuff like the guy from Racer X...

you have three systems in play here...
electrical; fuses, relays, switches and motors
mechanical; all the "hard parts" including the hubs (which you can't even count on a Warn to be engaged when it says it is, but that's another thread)
and the vacuum system; pump, valve, reservoir, lines

any one component of which will "make the 4x4 not work"

My low range an 4x4 light are both on an my 4wd does not work

on a truck where the ESOF hubs have been replaced with warns,
would generally lead me to think that the system electrically is fine, as you need to have the truck in neutral for the PCM to shift the motor between ranges, and the light on the dash indicating 4x4 or Low Range takes is triggered by the plate switches in the range motor.
The sequence is,
command 4x4 from the dash,
the PCM closes the 4x4 relay,
sending power to the shift motor and hub vacuum switch
which shifts the transfer case, and draws vacuum from the hubs
until
the plate switch in the motor closes (or opens, I'd have to look)
telling the PCM to shut the motor off
by opening the relay
and then turning on the dash indicator light

Which leads me to question:
are the front hubs BOTH engaging, or is one hung up, causing the front differential to not drive that particular wheel?