How to find wires without disassembling the harness.

[OldReno]

How to find wires without disassembling the harness.

Lots of people think right away that problems are associated with the machine harness, or loom, which is the nerve column of the machine.
Generally this is NOT a problem.  In fact, you can often do more damage to your machine by tearing apart those Beau plugs than just leaving it alone.
If you need to know where a wire goes, to check point to point through your plugs, the simplest way to find out where a wire connects is by looking at the MALE side of the plugs.  Your reel mech has two male plugs.  You can pull it and look at the wiring, and then using a bit of logic determine where that wire goes on the Female side. 
In other words, you don't need to tear apart the female Beau to see what wires are there.  The male side will tell you. 
So, pull your other sub-units out, and look at their male side to determine where that elusive wire you're looking for is. Make a simple chart if you need to (recommended).
And then, with your meter on Ohms, and power plug pulled, check point to point to verify that you have a connection.
You can use a paperclip stuck into the female side to hook your meter probe on.
Hope this is helpful,and that it may prevent you from un-necessarily pulling those female plugs out.  Every time you do that, you weaken the integrity of the machine's harness.
OldReno

[OldReno]

Another note, this is also a good technique if you want to chart-out your machine, or make your own schematic of what's going on.....
At least you can get a pin-out of your plugs, and that may help you with troubleshooting in the future.

[cowboygames]

I use a digital multi-meter on diode scale and a pair of alligator clips. After I find both ends of a wire then I can wiggle the harness to see if the tone cuts in and out. This tells me if the wire is faulty or not also. Works well when checking S2000 door harness'.

[OldReno]

Thanks Cowboygames,
This works well for just about any harness, and on most any machine.  And I often even use my very old logic probe (with built in battery).  You can also use an automotive tester, with battery and bulb. Sadly my hearing sucks, so using an audio device don't work for me.  BUT that's a great way to go if you can hear....
Yes, those old door harnesses are the worst, I agree, and don't forget to wiggle the crap out of them.
Thanks.

[stayouttadabunker]

My hearing is pretty bad as well.   
I could never hear the high-pitched tone on my multimeter. 

Sooo.... I dis-assembled the multimeter to get at the tone speaker. 
I drilled a small hole on the top front of the plastic housing next to the display,
and cut the wires from the tone speaker.
Then, I soldered them to a small, red LED and glued the LED lamp into the hole.

Now, whenever I get "continuity" reading, the red LED lamp lights up!   

[shortrackskater]

What? Speak up! Couldn't hear ya... 
I have hearing trouble too with certain tones.  I can be in a room full of people, with PLENTY of volume, look directly at the person speaking to me and I get
"bla waa waab laaa laaa faa bla bla"