4wd System Operation & Help Thread

Hey your doing better than most, most people are looking for a quick fix without putting in the legwork to test things.

 

Hey fellas, me again from earlier, with the pin 18 ground fix thing. So in my situation, i just used a suitcase clip over the wire and added a eyelet to the end and grounded to the nut that was right there. easily removable. I'm willing to chase this thing and see where the break point is if someone wants to talk me through it. Chasing wires isnt my favourite thing to do but i've certainly done enough of it over the years on all the farm equipment around here. Let me know. Kids are still in school this week so i should have the time.

 

I must have scrolled right past them.

 

Holy shit this diagram helped a ton. Thank you dude.

So if you’re thinking 18 is the culprit, those two are the grounds in the engine bay correct?

Since that ground is shared with the ECM’s in that diagram, wouldn’t I notice issues with them as well?

 

Not if it is the just that one wire from PA18 to EE.

 

Ahhhhhh I’m trackin’ now. So if that is the problem, it’s chasing that wire to the grounding point in the engine bay and finding an issue somewhere between the two. I’d imagine it’s just a straight shot Through the passenger side firewall?

 

If you are lazy (like me) you could just make your own ground. Splice a new ground wire into the wire coming out of PA18.

I don’t know how the wires are routed.
But you could look if you want to?
Just not sure it’s worth MY time.

 

I would suspect it would be broken somewhere near where it attaches to the cylinder head but it could be anywhere in the harness from EE to PA Pin 18.
Trace the harness out and look for damaged areas and where it could be rubbing on something and give the grounds a tug to make sure they aren't broken internally.

 

Need to confirm that's the problem but yea basically you gotta follow the harness and look for damage and give the ground wires the tug test to make sure the wire isn't broken internally.

 

@TacoZim

If you can’t tell by now.
@Dm93 is the type of guy that finds problems.
Figures out why you have the problem.
And fixes it correctly.

I’m the type of guy that finds a problem and fixes it with my bubble, duct tape, shoestrings and super glue.

The only thing we have in common is, finding the problem.

He is a Technician. He finds problems other people caused.
I’m not a technician. I find problems I caused (usually)

 

***Update***

Okay boys so just did a sanity check from the beginning by checking mechanicals first.
I shit you not. This thing is no longer in 4wd. The wheels do not spin opposite and the driveshaft can be spun by hand. The only thing I can think of is that I checked both before pulling completely off the driveway to do the checks going in forward/reverse and it unlocked itself?

So, with all of that. Truck is now mechanically in 2H which the position switches show.

Now. Where from here?

Just put Cab switch to 2H. Then put negative terminal back on battery. Put key in and lights still flashing. Gonna recheck all voltages to sanity check and will report back.

 

Updated voltages.

I never said I was a smart man.

TL1 12v in 2H. The rest remained the same. Red pen is today’s readings.

So given this. Sounds like the TC actuator is the issue and is out of sync? Front diff is reading correctly since now I see mechanically everything is 2H, but won’t lock due to the TC being the issue correct?


Edit* - idea here. Couldn’t I use a AA or 9V on the leads at the actuator to reverse polarity the motor back till it reads 0v at TL1. But since I’ll have to unplug the harness to get to it all. I’d have to get readings from the TC actuator itself.

Does that sound right or am I just trying to avoid taking the thing off? Lol

 

None of your TL wires are being pulled to ground.
Have you made sure the ground wire is good?
That would be pin #10 of the PA connector.
That’s why Dm93 asked you to check those earlier.

You could also unplug the TC actuator and check the the white/black wire for a ground. But you already know the inside of the truck. So might as well start there.

 

I was ass backwards. I thought because I’ve got 12v across TL1-3 that meant it was stuck between 2H and 4H.

Okay more numbers for ya.
PA 6,7,8,18,19 all 0v

PA 10 is 11.4v

Ground Wire is 0v at the T4 connector.

 

PA10 we are not concerned about it doesn’t have anything to do with the system.

Dm93 probably has a better way to check it.
But here is what i would do. I would unplug the TC actuator and check that the ground wire is good.
Personally, I’d use a test light.
If you don’t have one, You can check for continuity between the white/black wire of the Actuator plug and body ground.
If that is good, move to the actuator itself.

Check continuity between pins 5 and 4 of the actuator itself.
We are checking timing here. (Kind of, it could be bad contacts inside)

 

When you said Pin 10 on PA, did you mean something else? I thought it meant PA 10.

Will check 5& 4** next

 

You are absolutely right.
I made a mistake, I should have said PA 19. NOT PA-10
That’s what I get for trying to do this on my phone. Tiny pictures to work with.

 

All good dude I’m literally laying under my truck while my fiancé’ is sitting driver seat drinking a beer while I’m motherfuckin this truck to oblivion.

now checking continuity on 5& 4. Do you mean just probing the pins of the Actuator with the T4 unplugged? Not the T4 connector pins?

 

Yes, that is exactly what I mean

 

We need to check the wire integrity between pa19 and the actuator.
With T4 connector unplugged, see if you have a good ground on the white/black wire.
Again, I like to use a test light. But you can use continuity on the meter if that’s all you have.

If