4wd Light ? (1 Viewer)

[bigfj62]

Hey guys I picked up a Fj62 project for cheap. Had something happen after I worked on the dash that has baffled me a bit. I took the dash and gauge cluster out of the truck to work on the radio. I plugged everything back in and went for a drive. The 4wd light was illuminated so I assumed I had turned it on when messing with the dash. To my disbelief it was in the off position. Why would my 4wd light be illuminating opposite of what it should be? Pushed in ON light is off, Button depressed for off light is on. Doesn't make any sense to me.

 

[3_puppies]

are you certain it isn't in 4wd? have you tried turning the driveshaft?

 

[Seth S]

are you certain it isn't in 4wd? have you tried turning the driveshaft?

This /\......I believe the light turns on as a combination of the switch on the dash and the switch on the transfer case.

 

[Lead Head]

The light on the dash is controlled by a sensor down on the transfercase that detects the position of the 4WD shift mechanism.

The switch on the dash only controls the VSVs that engage/disengage 4WD. The behavior you describe can happen if you connect the vacuum lines up backwards to the VSVs. But if you didn't mess with the lines, it seems more likely that you somehow disturbed the plug going to the 4WD switch, and now it's working in reverse.

 

[bigfj62]

Plugged and unplugged the switch no change.

 

[OSS]

I don’t know specifically what happened but if you unplugged any wires on the gauge cluster- chances are good they weren’t plugged in the same way when you buttoned it back up.

 

[3_puppies]

is it in 4wd?
does the driveshaft turn by hand?
did you ever try the system out before taking the dash apart?
the solenoids could just be bad
hook the hoses up the other way and see if the light goes out

 

[bigfj62]

When the light is on it is for sure in 4wd but the button is off. I have unglugged the switch and tried reversing it but it just does the opposite when I plug it in. I understand wiring and have worked on these trucks for years this one has baffled me a bit.

 

[3_puppies]

it is not in the wiring
you need to switch the vacumn lines on the solenoid to get it to go back into 2H
was this the first time you used 4wd?
there is a cheap fix for this listed somewhere in the 60 section.

 

[bigfj62]

So someone must have had the vacuum lines switched over the years. I suppose that makes sense. Yes...new cheap project first time i've had it in 4wd.

 

[3_puppies]

So someone must have had the vacuum lines switched over the years. I suppose that makes sense. Yes...new cheap project first time i've had it in 4wd.

NO the lines are hooked up correctly, you switch them to run vacumn the other way to dis-engage 4wd. then switch them back and it will stay in 2wd until the button is pushed again. the problem is the solenoid. there is a cheap fix using a solenoid valve

 

[Randy88FJ62]

I did the write up about the $17 replacement solenoid I stole off the 3FE yahoo group years ago When the 4WD VSV fails it locks the 4 Hi position and the front driveshaft is locked. People would get around this by swapping the vacuum lines on the VSV solenoids.

Back to your post. Is the issue fixed? I swapped my A440F transmission years ago and after all said and done the light is always on regardless of the 4WD system. It is possible the wiring to the switch on the transmission has shorted or has failed. I haven't looked at the wiring diagram in a few years. If you need it pm me and I'll send you a drop box link.

 

[bigfj62]

That’s the thing….4wd is not stuck in. Front driveshaft spins freely when light is off.

 

[3_puppies]

That’s the thing….4wd is not stuck in. Front driveshaft spins freely when light is off.

do you understand how the 4wd engagement works in a US 62 series?
did you get it into 2wd?

 

[bigfj62]

H4 switch in off position, light is on, driveshaft does not move when I reach up and try to grab it meaning 4wd is engaged.
H4 switch is in the on position, light is Off, driveshaft spins freely when I reach up and grab it meaning it is not engaged.
I have rebuilt a slit case out of a 60. I know the big difference between the two cases is 2wd-4wd is engaged by vacuum in the 38mm us spec cases. While the 60 split case is manually engaged.

 

[3_puppies]

if the light is working opposite of the way it should?
chances are someone was in the transfer case at some point and the shift rail is wrong, meaning the detent for the switch is wrong.
the switch is a push button that rides on the shaft/rail, there is a detent where there shouldn't be and there isn't a detent where there should be one.

 

[bigfj62]

if the light is working opposite of the way it should?
chances are someone was in the transfer case at some point and the shift rail is wrong, meaning the detent for the switch is wrong.
the switch is a push button that rides on the shaft/rail, there is a detent where there shouldn't be and there isn't a detent where there should be one.

The light is working correctly.....the Dash SWITCH is not in the right position when 4wd is engaged and the light is on.