97 FZJ80 CDL Issue (1 Viewer)

[Connorrw]

Hello All,

I am here trying to get some help on a CDL issue I've been having after doing the 7th pin mod. I've found lots of similar threads, but nothing that describes what I am seeing.

Background -
I did the 7th pin mod following Slee's guide. I pulled a hazard switch out of a parts truck to use, plugged it into the factory harness, and removed the jumper. I then pulled the 10th pin incorrectly from the transmission control relay. This is the blue and black wire instead of the black and blue wire. I repinned it and then pulled the correct wire.

At this point, I tried my new CDL button and got nothing. Immediately before I did the mod, the actuator worked and the CDL locked when shifting the transfer case.

Troubleshooting -
Following the other threads on this forum, I tested a bunch of stuff. I used a desktop power supply at 9v and individually checked each relay on the transmission control module. All good and independently switched.

Using the EWD, I checked continuity from the control module to the actuator. Except for insulation being different colors, all 4 wires at the transfer case actuator had continuity to some pin at the control module.

I used a paper clip and checked the lockup sensor. The dashboard light came on without issue.

Not sure what relay, but when I hit the CDL button, a relay in the control module fires. This also happens if I revert to stock and repin/re-jump the harness and switch to low range.



Any ideas? Am I missing something easy?

 

[Evil80Forces]

Welcome to a life of ****ed up CDL issues that only happen when it's over 97.3 degrees F outside, or accelerating up hill, or specifically turning to the right or a combination of them all.

Which no mechanic can ever figure out, and every thread you find online about your specific issue will never have a post from OP solving it.

yes i'm bitter

 

[ppc]

Troubleshooting

I used a paper clip and checked the lockup sensor. The dashboard light came on without issue.

Not sure what relay, but when I hit the CDL button, a relay in the control module fires. This also happens if I revert to stock and repin/re-jump the harness and switch to low range.



Any ideas? Am I missing something easy?

First line quoted... Sure sounds like the only problem is the CDL Indicator Switch/Sensor located at the top front of the transfer case.

Second line,... Sounds like it is operating as expected.

 

[Connorrw]

Haven't figued out anything more. Shelved until trails close for the winter.

 

[fjbj40]

When it comes to troubleshooting everyone depends on “continuity”

Load is better, and using 9 volts in a 12 volt system is !

You’re saying it’s not lighting up the dash light?
But are you checking to see if it is actually locked?
Jacking and rotating a tire to engage?
Are you hearing the cdl actuator motor engage?
If you hear the motor, rotate tire to engage and still no light? Then switch on top fwd of Xfer case is culprit.

It is a basic system.