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- As the name implies, connectors are how we connect our wiring harness to the electronic devices, sensors, and actuators fitted to the engine and vehicle.
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00:09 |
As our harness branches out to each device each branch will always end with a connector, whether this is a simple ring terminal or an autosport connector with over 100 pins, it should never be a bare wire.
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00:20 |
Our wiring harness construction is not complete until every branch is terminated with a connector of one form or another.
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00:27 |
When we need to interface with OEM electronic sensors or actuators, there is a truely massive range of connectors used in the automotive world.
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00:34 |
Sometimes it can be a real struggle to identify a particular connector on an OEM component, and in addition to this once we do identify the connector we need, actually sourcing it can turn out to be impossible.
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00:46 |
They may only be available to OEM manufacturers or have large minimum order quantities.
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00:51 |
If you need help identifying a connector, create a post on our forum with the application information and any photos you can take, and we'll try to assist with the identification.
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01:00 |
In the practical tools and wiring harness construction skills section of the course, we'll look at a couple of common OEM connectors, how to crimp their terminals and how to pin and de pin the connector bodies.
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01:11 |
Thankfully the range of connectors used in the automotive aftermarket is much smaller and better documented.
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01:17 |
Any aftermarket automotive electronic device should be supplied with a connector or detailed documentation as to the required connector.
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01:25 |
Most often the connecter we are fitting to a wiring harness is defined by the device it connects to.
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01:30 |
But if you're in the situation where you're able to specify the connector yourself, such as joining the main wiring harness to a sub wiring harness, or if a sensor or actuator is supplied with a pigtail of wiring and you need to add a connector, there are several key factors to consider.
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01:45 |
The first consideration is the number of wire connections you need to make, as this will determine the minimum number of pin positions the connector requires.
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01:52 |
The difference commonly used connectors are available in various versions with different numbers of pin positions, and most likely there will not be a connector version with the exact number you require.
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02:02 |
Selecting a connector with more pin positions than you need and leaving some unused is not a problem though.
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02:09 |
The next consideration is connector sealing.
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02:11 |
If the connector is going to be inside an enclosed cabin such as a modified street car interior then an unsealed connector can be used.
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02:18 |
If the connector is going to be exposed to the atmosphere, such as in the engine bay or under the chassis, it needs to be a sealed connector to protect against the ingress of road grime dust and moisture.
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02:29 |
A sealed connector will have silicone rubber gaskets, that seal where each wire enters the connector body.
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02:34 |
These may be installed onto the wire itself, becoming part of the crimped electrical terminal, or integrated into the connector body.
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02:41 |
The connector bodies, both the male and female ends, will also have gaskets that seal their mating interface.
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02:47 |
You need to have a very clear idea about the amount of current that will pass through the connector pins, as the connectors will have a maximum allowable limit.
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02:55 |
As current passes through each pin connection, the small resistance it encounters generates heat.
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03:00 |
If you try to pass too much current through the connector, too much heat will be generated and the connector body will melt, possibly leading to a fire.
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03:08 |
The connector current limit decreases with ambient temperature too, so you need to take into account where the connector will be in the engine bay and what sort of external heat sources it might be exposed to.
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03:19 |
The final consideration to keep in mind, is the cycle rating of the connector.
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03:22 |
That is the number of times a manufacturer guarantees it can be connected and disconnected while maintaining its electrical conductivity.
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03:29 |
In relation to this is the retention method the connector uses when the two sides are mated to one another.
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03:35 |
It needs to have a positive latching mechanism to ensure it cannot vibrate loose.
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03:40 |
Price is of course a deciding factor.
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03:43 |
Typically the smaller a connector gets in relation to how many pins it has, the more expensive it becomes.
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03:49 |
Some of the professional motorsport connectors with more than 100 pins become eye wateringly expensive.
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03:55 |
But if the application calls for it, the price of a reliable connection is far less than that of chasing electrical problems on race day.
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04:02 |
With all these considerations in mind I have a go to connector range I use at the modified street car and club day track car level and that is the Deutsch DT range.
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04:12 |
They're a thermoplastic body with a maximum continuous temperature rating of 125 degrees celsius.
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04:18 |
They have integrated sealing gaskets and are easy to both insert and remove pins from without special tooling.
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04:24 |
They have a cycle rating of at least 100 connections and disconnections and are very common and reasonably priced.
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04:30 |
They're available in three different current handling ranges, the DT mini, or DTM, which accepts wire up to 18 AWG in size and can handle 7.5 amps per pin.
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04:41 |
The DT which accepts wire up to 16 AWG in size and can handle 12 amps per pin.
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04:47 |
And the DTP or DT power which accepts wire up to 12 AWG in size and can handle 25 amps per pin.
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04:55 |
Each size range is available with various numbers of pin positions, meaning it's almost always possible to find a connector in the range to suit the application.
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05:05 |
In the practical tool and wiring harness construction section of the course, we'll go through the crimping, pinning, and de pinning of each of these connectors in detail.
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