Rear door wiring loom diagnostics

[RockDriver]

I've been toiling away trying to fix my rear right door actuator. The actuator itself does work directly with a tester, but not plugged in, likely because one of the pins in the socket seems to be dead. So my attention is now on the rear right door wiring loom which looks like this:

From what I gathered so far it comes out of the door and into the right middle support (not sure if this is the correct name) where it's plugged in. The harness has a lot of points of attachment inside the door and so far I haven't been able to find a video how to remove it, so I'm a bit reluctant to proceed - I don't want to make things worse.

What's the best way to diagnose if a cable is broken somewhere? Does the wiring loom have to be removed? 2001 HDJ100.

 

[Zuberg]

Test for continuity with multimeter. If you don't know how to do that, then youtube has a ton of videos on basic electrical diagnostics. You know which wire/pin isn't getting power so carefully remove the wire wrap/tape and test. If you need to remove the harness, a heat gun with low heat on the plastic wire mounting clips should minimize the risk of breaking the old plastic. I'd start with making sure power is coming from the fuse block and making it as far as door harness connector. Then you would know for sure the issue is in the door wiring. Basically, start with the power source and work towards the wire termination in the door.

Go to resources for the electrical wiring diagram (EWD) which are imperative for anyone diagnosing electrical systems on these trucks. I'm a paper guy so I just buy the EWD books for cheap on Ebay. Year and model (100 vs LX470) matter so make sure you have the right one for year and make.

Resources

forum.ih8mud.com