If ctr lock bulb is out, will F/R lockers not engage?

[IdahoDoug]

My truck won't give me a light in low range to indicate the ctr lock is engaged automatically. From putting the key to the "on" position to get all dash lights on, the F/R light bulbs light with everything else, but not the amber center lock icon. So, I'm assuming the bulb's out. But does this disable the F/R lockers??? It would make little sense to have a burnt out bulb out in the middle of nowhere disable the lockers, but that appears to be the case. Any firsthand knowledge out there while I read the FSM to decipher it?

Thanks.

DougM

 

[Big_Moose]

Doug

Yes the lockers will engage / disengage with or without the "light bulb" function, as long as the switch has engaged the CDL motor

Joe

 

[Heffenoche]

Does your ABS light still come on but CDL doesn't? If so then I would think that the lockers would still lock. If it doesn't then you may have a differnt problem

 

[IdahoDoug]

Good point - no ABS light, either. Hmm, time for a search as I recall there's a connector I need to clean.

Since the switch for the CDL many have retrofitted simply plugs into a connector behind the switch blank, I'm going to look for that connector and manually lock my CDL with a jumper wire. Anyone know which terminals to connect? This will save me work/time.

DougM

 

[RavenTai]

I think it was PPC that posted the schematic for the trucks with the CDL switch from the factory, you could use that to fake the presence of the switch, unfortunately it was lost in the forum software change, the 96 EWD just shows the jumper all the unused circuits are not illustrated even though they are still present


There could be a problem at many spots, two switches are the most suspect
The Low 4 switch (T3) tells the CDL relay box that the transfer is in low (through the infamous pin 7)
The CDL relay box then commands the CDL actuator towards lock, when the actuator makes lock the CDL indicator switch (C2) powers the dash lights

my guess is the low 4 switch

Try turning the key on but engine off (so you can hear) and move from high to low, see if you hear the actuator turning if so then the low 4 switch is good if not I would start there any work your way down

Jumping the two pins of the Low 4 (T3) will bypass the switch

This picture should get you to there

 

[RavenTai]

link to related post: https://forum.ih8mud.com/showthread.php?p=198771#post198771

 

[landtoy80]

The pic of the t-case jogged my small brain

When I had the same problem, I got one of my Position Switchs (from my old t-case) and plugged it into the L4 wireing harness from the t-case. I then with the key "on" motor off, pushed the switch (its a ball with a spring switch) and had the wife look at the dash. The ABS and CDL lights came on. I think the ball must of been stuck somehow (don't know why as it was only a year old new t-case).

Somehow you need to remove the switch (don't know if you can do it without removing the t-case) and push the ball to test the switch.

Note I don't remember if the switch lights up the light when the ball is pushed or at rest. I would put $$$ on the dash lights up when the ball is pushed.

You might be able to remove the switch from the rear or front diff lock or the other switch on the t-case if you can get to it.