Trailer Electrical Splicing question

[airbornebandsman]

I am in the process of splicing a truck side (female) trailer plug into the existing electrical system on an M200A1. I seem to have an extra line on the truck plug side I am splicing in. Here is the markings on the wires:

Existing wiring harness: Plug I am Splicing in:
-24-484
-24/483
-22/461
-23
-21
-22/460
-90A (Ground)
-37 (capped)

Plug I am splicing in:
-24
-24
-22/461
-23
-21
-22/460
-90 or 06 (Ground)
-490

The one I unsure of is 490 (Space H on the plug as far as I can tell) I am not certain if it needs to be connected or if it should be capped (like 37). Anyone have any ideas.

 

[rosco]

Its easy to feel like the wires are scrambled, as there are numerous diagrams, and they are often "just a little different". For instance in the 1st diagram, the Domestic 7 pin, is for 7 round pins or OTR trucks. That's different then the 7 flat pins or RV plug. My application is M35 Cargo. The wiring diagram that I use has 490 as an optional accessory. Namely when the M35 is setup with 5th wheel as a tractor - then its for back-up lights. When I modified the standard plug, and added 7 round pin plug, I carried the back-up lights to the 490, H pin on the truck. Trailers, may or may not be wired to use it.

Hope I haven't confused things more by rambling. The short answer is, you don't have to carry it.

 

[airbornebandsman]

Thanks. That is sort of what I. I am seeing up an M200A1 to haul an M373 trailer and want to make sure the lights work correctly. Also wondering if anybody knows which circuit the clearance lights run off of?

 

[tobyS]

From the first diagram it would seem to be E.

Don't forget to check your male and female pins for corrosion. I chased wires a long time and found the plug not making connection from a boundary layer on the pins (a civilian version).

 

[73m819]

H may be a 24v hot wire, tractors have this added wire, with NOTHING on, check for 24v, with the pulling trailer plugged into the tractor, this 24v hot wire is for 24v lights in a trailer while enroute.

 

[airbornebandsman]

H may be a 24v hot wire, tractors have this added wire, with NOTHING on, check for 24v, with the pulling trailer plugged into the tractor, this 24v hot wire is for 24v lights in a trailer while enroute.

Sweet, The trailer I am splicing into does not have the H wire coming from the harness. Not to concerned about interior lights being on. As long as the clearance and exterior lights work I am happy.

 

[tobyS]

It appears you need to identify by using a test light as the drawings above seem to conflict a bit. On wiring 5, it appears the clearance lights connect into wire 21 and that is E, I believe.

Ron, is H hot and not switched? On wiring 5, I see it is tied to wire 24 and tied to A and C also. That would be switched with running lights so should work there.