CDL diagnosis question (1 Viewer)

[Evil80Forces]

The other weekend I was scootin down a dirt road and notices my CDL light kind of flashing like what you'd see with a bad electrical connection. I disengaged and reengaged and the light then stayed on.

When finished I disengaged the CDL and went back into 4H and the light didn't turn off and it wouldn't turn off.

Went out again on a recovery this last weekend and after some very rough and bumpy roads it has now turned off, but now won't turn on when shifting into 4L.

Jacking up one front tire it appears it's still locked though, tire wont spin, front locker is not engaged.

I've benched tested the CDL relay and it all checks out.

I've verified the L4 and Neutral switches work and make good connection when shifting the transfer case.

I've verified the CDL plug lights up the dash when jumped.

I've verified the CDL switch works, and is not being triggered by the diff lock mechanism... (This is where I'm a little confused...)

Can the CDL be engaged but not engaged enough to trigger the CDL light? This is also confusing me because during the recovery I ended up digging ruts with my rear tires, and was told my fronts weren't turning...

So how can it be engaged but NOT engaged?

Any helpful thoughts?

 

[CJF]

Jacking up one front tire it appears it's still locked though, tire wont spin, front locker is not engaged.

What gear was the transmission in?

I haven't thought about this in a while, but I'm pretty sure if it wasn't in neutral the tire won't spin even with the center unlocked.

 

[Evil80Forces]

What gear was the transmission in?

I haven't thought about this in a while, but I'm pretty sure if it wasn't in neutral the tire won't spin even with the center unlocked.

Ok, new data.

Just ran out and checked again. Truck in neutral the front tire WILL spin. So CDL is not engaged.

This is looking more and more like a bad CDL actuator now... dang it.

 

[ppc]

^^^^^^. This either need one wheel on each axle raise or the transfer in. Neutral or park, neutral preferred with less resistance only rotating transfer case instead of transfer+transmission.

As far as the lights go, the CDL can get sticky from lack of use. Flickering lights point more to the 4Low position and CDL indicators not giving consistent output.

If you have the dash switch then I would start by. disconnect the 4Low position indicator and do more testing.p

 

[ppc]

Ok, new data.

Just ran out and checked again. Truck in neutral the front tire WILL spin. So CDL is not engaged.

This is looking more and more like a bad CDL actuator now... dang it.

I agree that would be unlocked but certainly not conclusive the actuator as I stated above still could be either sensor switch.

 

[Evil80Forces]

^^^^^^. This either need one wheel on each axle raise or the transfer in. Neutral or park, neutral preferred with less resistance only rotating transfer case instead of transfer+transmission.

As far as the lights go, the CDL can get sticky from lack of use. Flickering lights point more to the 4Low position and CDL indicators not giving consistent output.

If you have the dash switch then I would start by. disconnect the 4Low position indicator and do more testing.p

See my reply.

CDL is not engaged per wheel spin test in N.

L4 and CDL switches have been replaced.

L4 gives good signal when t-case is shifted into 4 low.

 

[ppc]

Are these new sensor switches and dash switch OEM?

We're not posting in sync so. Take my responses may not be to your very last post.

 

[Evil80Forces]

Are these new sensor switches and dash switch OEM?

We're not posting in sync so. Take my responses may not be to your very last post.

Yeah, will try to keep on track.

The sensor switches are not OEM but they are very simple designs and I tested them before installing, they should be fine for at least testing all this... (I installed them like 2 hours ago so they are brand new, still no luck).

 

[Evil80Forces]

Are these new sensor switches and dash switch OEM?

We're not posting in sync so. Take my responses may not be to your very last post.

Looks like I'm going to need to somehow get to the CDL plug and test that it is getting 12v when I shift into 4L.

I can hear the CDL relay clicking when shifting it, and it tested good.

 

[ppc]

There have been a few posts within the last couple of years where the Beck-Arnley had a problem where the length going into the transfer case was to short or had an extra washer with the same result.

 

[ppc]

I think the actuator has built in llimit switches like the front and rear lockers have. Those limit switches could be corroded or the actuator needs to be re-clocked which requires removal of the actuator and opening the guts up.

 

[Evil80Forces]

There have been a few posts within the last couple of years where the Beck-Arnley had a problem where the length going into the transfer case was to short or had an extra washer with the same result.

mmm, from my understanding of how the cdl relay and mechanical system works,

when shifting to 4 low, the L4 switch is engaged, which sends signal to the cdl relay telling it to activate the cdl motor. only when the cdl motor makes its shift to "cdl locked" does the cdl switch engage, lighting up the dash.

I know my L4 switch is working properly and sending signal back to the relay. So if my relay is good and is sending signal to the actuator, but it's not shifting, that should point to the actuator quitting on me.

 

[Evil80Forces]

I think the actuator has built in llimit switches like the front and rear lockers have. Those limit switches could be corroded or the actuator needs to be re-clocked which requires removal of the actuator and opening the guts up.

yeah, i think that's what's going to have to happen. i can then bench test the actuator when it's out as well.

 

[ppc]

The limit switches are internal in the actuator

 

[Evil80Forces]

The limit switches are internal in the actuator

yeah, the limit switches will be internal and only tell the actuator when to stop and won't have any effect on the "cdl engaged" position switch. i'm not getting any actuator motor movement.