FIXED: 4WD light flickering, 4WD light flashing and sloppy transfer case shifter

[Twoscoops]

I thought I'll post this to let you guys know how I fixed 3 title mentioned problems (Cost $40).

It started with a flickering 4WD green light on the dash that was bothering me and after reading numerous thread on forums I decided to remove the centre console to get access to the transfer case switches that operated the 4WD ECU. Actually there is 3 switches, the 3rd is the free wheel switch located on the front diff.

First I removed the transfer case shifter entirely to access the 2 switches on top of the transfer case and I noticed the shifter bush/bearing was absolutely smashed to pieces hence a sloppy shifter. Got a bush from ebay for $40 and replaced it. (note that if you attempt to do this, the bush is held by a pin and it is a pain to remove. I used a bench vice but it was a bit dodgy) anyway sloppy shifter is now fixed.

I unplugged the two switches on top of the transfer case (very awkward access) clean them and use a lot of electrical contact spray). 4WD flickering light now fixed.

Couple of days later I was welcome by a flashing green light when in 2WD which became a solid green light when shifted in 4WD.
This linked helped me somehow:

http://4wd.blogeasy.com/

Traced the problem by unplugging the 2 vaccum lines on the 2 solenoids (blue and yellow dot) below the air box attached to the inner wheel guard (driver side)
You should have suction on the yellow dot solenoid when in 2WD and suction on the blue dot solenoid when in 4WD. I had no suction on the yellow dot solenoid whatsoever in 2WD meaning the actuator rod was not "activited" (free wheel switch was giving me the flashing light).
I removed the bracket holding the solenoid (I removed the air box first for easier access) Noticed that the electrical contacts where corroded/oxidised. Cleaned them and spay them with electrical spray and solenoids are back in action and problem fixed.

I hope that can help someone if you can understand all that blah blah blah.

Good luck. ERIC.

[cookie]

or just install manual front hubs and never have to worry about it again :-)
best thing i've done on mine

[fgin]

I thought I'll post this to let you guys know how I fixed 3 title mentioned problems (Cost $40).

It started with a flickering 4WD green light on the dash that was bothering me and after reading numerous thread on forums I decided to remove the centre console to get access to the transfer case switches that operated the 4WD ECU. Actually there is 3 switches, the 3rd is the free wheel switch located on the front diff.

First I removed the transfer case shifter entirely to access the 2 switches on top of the transfer case and I noticed the shifter bush/bearing was absolutely smashed to pieces hence a sloppy shifter. Got a bush from ebay for $40 and replaced it. (note that if you attempt to do this, the bush is held by a pin and it is a pain to remove. I used a bench vice but it was a bit dodgy) anyway sloppy shifter is now fixed.

I unplugged the two switches on top of the transfer case (very awkward access) clean them and use a lot of electrical contact spray). 4WD flickering light now fixed.

Couple of days later I was welcome by a flashing green light when in 2WD which became a solid green light when shifted in 4WD.
This linked helped me somehow:

http://4wd.blogeasy.com/

Traced the problem by unplugging the 2 vaccum lines on the 2 solenoids (blue and yellow dot) below the air box attached to the inner wheel guard (driver side)
You should have suction on the yellow dot solenoid when in 2WD and suction on the blue dot solenoid when in 4WD. I had no suction on the yellow dot solenoid whatsoever in 2WD meaning the actuator rod was not "activited" (free wheel switch was giving me the flashing light).
I removed the bracket holding the solenoid (I removed the air box first for easier access) Noticed that the electrical contacts where corroded/oxidised. Cleaned them and spay them with electrical spray and solenoids are back in action and problem fixed.

I hope that can help someone if you can understand all that blah blah blah.

Good luck. ERIC.

I have a 99 NL GLS

With the help of this thread and http://4wd.blogeasy.com/ I was able to diagnose the 4wd (front wheel) lights flashing and fix it (at least for now). Started flashing yesterday as I was pulling into the driveway. Thought it will go off on its own as it has a few times before but it kept flashing the whole day and was annoying as ever knowing there was something wrong. Tried shifting through 4wd without any luck. When it was on 4wd all lights kept on as it should. Even the CD light behaved as it should. Only when you go back to 2wd the 2 front wheel lights kept flashing.


First thing I checked was the yellow/blue solenoids. Checked suction on the hoses coming from the car and it had pretty good suction.
But, I had no suction on the yellow dot solenoid in 2WD like you. The blue one has suction. So swapped the hoses and the light stopped blinking. However the solenoid was clicking which means the electrical contacts were fine. So took out the bracket holding the solenoid and took the whole thing out. Didnt need to remove the air box but was a bit tricky.
Anyway blew into the solenoids quiet hard a few times while I had the ignition ON with the wire just touching the contacts on the solenoids and then pulling out, then touching it again. This seem to make it work again. When the hoses were plugged in the lights stopped flashing in 2wd. Went for a short drive shifting through all 4wd positions and eveything seems back to normal.

Anyway could someone let me know if there is a better way of cleaning out the solenoids? Or should I be replacing them ? Any advise is welcome.

Thanks

[flyinwall]

i fixed my flashing light just by going 4wding (i hadnt been 4wding for quite a while and the light was giving me the shits and i decided to go for a wheel and it has not flashed again since i went wheeling)

[Tommo98765]

Plenty of threads on this issue.

The first thing to do before pulling anything apart is to check the vacuum operated module located in the engine bay, mounted on the drivers side wheel arch, as mentioned.
When the module doesn't supply the correct feedback, the green light will flash. Mine was due to the connector on it being corroded. Cleaned it up and it was all good. I ended replacing the module as it was only $80 for a pair from car electrical store (Coventrys from memory maybe?).

The other thing to check with out taking anything apart is the actuator which engages the diff apparently. I didn't have to do this so im not 100% sure.

Please be aware, the challenger hubs are always engaged, so expect to see the opposing wheel spin if you turn one wheel (while the front of the car is raised obviously) even in 2wd.