Design of Air Conditioning connection cables Assembly

When we consider the cost-reduction design of wire harnesses, we require the use of as few wire harness connectors as possible. However, I believe everyone has encountered this situation recently. More and more OEMs have separated the air conditioning wiring harness on HVAC from the instrument wiring harness. Now the question comes, is it necessary to split?
We know that if the air conditioning wiring harness is separated separately, the cost of the wiring harness will inevitably increase. A pair of connectors are added to connect the air conditioning wiring harness and instrument wiring harness.

Design automotive air conditioning wiring harness

At the same time, the splitting of the air conditioning wiring harness will bring the following benefits:
1. The air-conditioning wiring harness is supplied together with the HVAC, which can shorten the assembly time of the main engine factory.
2. Convenient assembly
3. Contribute to the modular design of wiring harnesses
But beyond that, are there any other considerations?
Wire Harness Engineer Scatter saw an article recently. The point of view is probably that if the air-conditioning wire harness is not segmented, the instrument wire harness will come down from the relatively stationary instrument pipe beam and be assembled to the HVAC (there will be vibration when the HVAC is working). The constant vibration of the wiring harness caused fretting corrosion of the terminals, which eventually triggered a car recall.

Wrapping and fixing of automobile air conditioning wiring harness

Then we have to ask, does it have to be segmented?
My point is, it should be analyzed on a case-by-case basis.
When designing the CATIA wire harness layout, the wire harness layout in the vibration area and the wire harness layout across relatively moving components are our key considerations. At this time, the central guiding idea is: how to reduce or even eliminate the impact of movement on the wiring harness connection performance as much as possible.
There are a few points to pay attention to:
1. Eliminate the stress concentration problem on the wiring harness terminals as much as possible to avoid subjecting the connecting terminals to additional pulling force.
The main methods to eliminate stress concentration in wire harnesses are:
a. The wires at the end of the plug-in must not be wrapped loosely

Routing of air conditioning wiring harness

The wires at the end of the plug-in should not be wrapped too close (Note: the length of L generally refers to the distance between the farthest terminals of the connected plug-in)
The wiring harness at the end of the plug-in needs to be effectively fixed within 100mm.
2. Analyze the relative movement distance and reserve the length of the wiring harness. If the wire harness is segmented, the Inline plug-in must be effectively fixed (rotation is not possible)