Yep, you're right.
The large difference in height (from post entry to exit points), the short distance transited in the horizontal plane, the stickiness of the rubber conduit and the confined spaces in which to work on either end...makes fishing/pulling wires into the door panel a huge challenge.
It is almost not even worth trying - using traditional methods. This is especially true if you have both P/L's & P/W's. The thickness of the wiring bundle - that is required to operate both those systems - essentially fills the openings in the steel of the door post, door skin and the conduit. It is marginally easier if only P/L's or P/W's alone are installed, but it is still a gigantic pain in the ass.
Some whiny little bitch recently wrote this about repairing a severed P/W power lead:
This was the first time I had ever dealt with the PW/PL harness on these trucks - maybe 12 years ago. By the time I got to the point in the job where a detailed failure analysis could have been conducted - I had a bad attitude to say the least (see below). It was like: "Jerry, never mind why it happened, just put the GD thing back together and hope you never have to do it again!"
The repair - the way I did it the first time anyway - is an absolute pain in the ass. This is because - if you want to retain the original wiring - the common harness connector under the dash has to be disconnected and the entire wiring group has to be pulled out through the opening in the body, through the rubber boot, through the opening in the door and finally out of the door cavity.
To make matters worse, I had PW & PL locks and the break was at the drivers door both...so the wiring group was as big as it gets. Because of the two master switches in the drivers door, the wire bundle to that side is basically double the size of what goes to the RH door.
The connector ends kept hanging up in the rubber boot, so that needed to be released by hack-sawing through the flange rivets. Of course at reassembly, the flanges had to be re-riveted.
Only when the entire harness is pulled and hanging out of the door - is it then possible to strip and splice the broken section.
While the actual splice is done in a minute or two, the harness pull (in and out) takes about 6 hours and slices the **** out of your hands and fingers.
So the repair is done. Now it's time to fish the harness back through everything and into the cab. Fugget about it!
If I thought pulling the harness out was an ordeal - pushing it back in made that look like a day at the friggin' beach!
Now when I pull that harness, the first thing that happens is the door is released from the hinges, the rivets for the conduit flanges are drilled out and the door is hung from a chainfall. Only then do I start to pull wires.
Here is one way to lead a speaker wire out of the cab and into the door without tearing everything apart:
1. Pick an existing wire in the PW/PL harness that can be used to pull the speaker wires through the door post, boot and into the door. Let's use the drivers side door as an example and designate the ground lead as the puller. The ground lead is not part of the main cross-cab harness. It separates from the rest of the wires immediately after entering the cab and goes straight to the ground bus block.
2. Pull the ground lead's terminal connector off the ground block.
3. Measure the distance from inside the cab to where the speaker will be mounted and multiply that by 3. That is how long your speaker wire needs to be.
4. Securely fasten one end of the speaker wires to the ground lead terminal connector using good quality electrical tape. Heat the tape up a bit to make it nice and stretchy and wrap it tightly. Try to keep the OD of the splice to a minimum.
5. Before you begin, test your splice by holding the ground lead in one hand and yanking hard on the speaker wires with your other hand. You do not want the splice to break during the pulling procedure - I am sure you can imagine why.
6. Using Vaseline or similar, lube the hell out of the exposed section of ground lead and the entire length of speaker wire.
7. Use a screwdriver, awl, needle nosed pliers, whatever it takes to pop the rubber grommet from the opening in the door post. The grommet has to come out - there is no way around this.
8. When you have it free from the opening, you will have to slice it open and pull it from the harness. Make a nice neat cut so that it can be glued back together when this is all over.
9. Okay it's time to pull your speaker wires into the door. Just reach into the door opening, grab the ground lead, say a prayer to whichever god you believe in and start pulling.
10. With any luck your splice will hold, and - after a few tense minutes - the end of the ground lead with the speaker wires attached will slither into the door hollow.
11. Alright, you did it! Your speaker wires are lead from inside the cab out to where the speaker will be. But the ground lead terminal connection is now inside the door and since it's not connected to the bus block anymore, the PL/PW systems are inoperable. You need to get the end of the ground lead back into the cab.
12. Break your splice and pull about half of the total length of speaker wire into the door. You made the speaker wires 3 times the total distance of the run so there will still be plenty left in the cab.
13. Make a new splice. This time tape the ground lead terminal connector to the speaker wires at a point close to where they exit the door skin.
14. Break out the Vaseline again and re-lube both the speaker wires and the ground lead.
15. Go into the cab and do just like you did when you pulled the speaker leads - but this time pull in the opposite direction.
16. Again, with any luck - and some patience - the speaker wire will pull the spliced-on ground lead through the maze and eventually the terminal connector should emerge from the hole in the door post.
17. Grab the ground lead and bring it in far enough to stab onto the bus block.
18. Snap the cut open grommet back over the harness, glue it together if you want and push it back into the hole.
