80 CDL trouble after bad decision (1 Viewer)

[916rockcrusher]

Being the impatient person I am I decided to try using an ect dash switch for my center dif lock. I didn't want to wait to have an actual switch shipped. It worked great until I turned it off. It turned off the center diff lock and abs lights and now they won't come back on. CDL isn't engaging either. My 80 doesn't have have factory lockers and from what I'm reading no diff ECM. No fuses blown. What could I have fried? What are the other wires in the harness besides the two needed to engage and disengage the CDL? Doesn't engage in 4L now either.

 

[richardlillard1]

I'm assuming it's a 93-94?

Did you do the 7-pin or pull the plug on the transfer case?

 

[916rockcrusher]

94. I pulled the plug out from under the dash. No pin 7 mod yet this was my first step.

 

[916rockcrusher]

Removed the cap with jumper wire which engaged my CDL. Stayed engaged with the switch in the on position. Problem happened when I turned it off

 

[916rockcrusher]

Figured out the problem. The wrong switch disengaged the diff lock but didn't take it all the way to the limit switch. The c diff relay didn't know which way to send the diff lock so it threw its hands up. I manually cycled the diff lock by applying ground and 12v to the correct pins then reversing polarity to disengage it. I was a knuckle head and didn't document which pins my apologies. Bought a diff lock switch from Slee and now happy trails.

 

[916rockcrusher]

Makes the light out in the rear defroster really stand out guess I need one of those too

 

[inkpot]

I'm assuming it's a 93-94?

Did you do the 7-pin or pull the plug on the transfer case?

DUDE! That is the PIN 7 MOD!
I thought we got that all cleared up LAST week?

 

[HotShot848]

So, i bought my 80 with the CDL not working. Prior owner did the 7 pin, transfer case spool and there is a ECT switch where the CDL switch should be and he hand wrote 4X4 on it. Prior owner said it worked when all that work was done and then parked it. After a few weeks later he tried it and it stopped working.

When i press the button, i can hear the rely click but i get no light or it doesnt engage. Could my problem be the button?

 

[916rockcrusher]

So, i bought my 80 with the CDL not working. Prior owner did the 7 pin, transfer case spool and there is a ECT switch where the CDL switch should be and he hand wrote 4X4 on it. Prior owner said it worked when all that work was done and then parked it. After a few weeks later he tried it and it stopped working.

When i press the button, i can hear the rely click but i get no light or it doesnt engage. Could my problem be the button?

My relay clicked too. When it works properly there are 3 clicks out of the relay and only one when it wasn't working. That relay seems to be bulletproof as I shorted it several times with the wrong switch and several more testing so I wouldn't worry about it going bad. The ECT switch will not work nor will the 80 hazard switch. Has to be a Tercel hazard or 8 diff switch. Unplug it ASAP. You're either going to have to cycle the diff lock manually or mine vibrated back to it's disengaged position over the course of a week driving the first time I messed it up.

 

[916rockcrusher]

So, i bought my 80 with the CDL not working. Prior owner did the 7 pin, transfer case spool and there is a ECT switch where the CDL switch should be and he hand wrote 4X4 on it. Prior owner said it worked when all that work was done and then parked it. After a few weeks later he tried it and it stopped working.

When i press the button, i can hear the rely click but i get no light or it doesnt engage. Could my problem be the button?

The diff lock has to be at the limit switch in either lock or unlock before the relay will engage. Yours is probably stuck somewhere in the middle like mine was.

 

[HotShot848]

I ordered a new switch, ill let you know how it goes when i get it. Thanks for the help!

 

[HotShot848]

I ordered and installed the new switch, but the transfer case is still not engaging. I think i need to cycle the diff lock manually, but I dont know how to do that. Can you guys help me out please?

 

[Rifleman]

I ordered and installed the new switch, but the transfer case is still not engaging. I think i need to cycle the diff lock manually, but I dont know how to do that. Can you guys help me out please?

I think you really need to think about buying, or downloading a copy of the factory service manual for your truck, it'll help you deal with problems like this.

 

[916rockcrusher]

The FSM doesn't give a ton of detail on cycling the CDL if I remember correctly. The safest way is to use a 9V battery so as not to fry anything or stretch the springs in the diff. If you're using the vehicle battery I would us a small fuse on your test lead to prevent damage. The motor has two wires and moves either direction when polarity is switched. I did mine under the dash using the harness for the relay. Without the FSM telling me which wires to use I would disconnect the harness at the t-case because there are only three or four wires to chose from. The motor is not grounded so you'll need to apply ground to one wire and power to the other. The motor will engage or disengage depending on which wire ground or positive is applied. You will hear the motor operating when power is applied to the correct wires.