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Jul 30, 2021


  • Technology

Drivers and technicians witnessing failing or non-operational lights and experiencing loss of continuity at the 7-way connection could be experiencing symptoms of pin degradation.  

If not rectified, pin degradation can affect a fleet’s bottom line when downtime and CSA violations are encountered. Time in the shop repairing the problem outside of routine maintenance means money lost on replacement parts, additional labor, and time away from the road when the vehicle could be in operation. This may cause a ripple effect, keeping other vehicles out of commission that may have been next in line for service.

What is Pin Degradation? 

So, what is pin degradation? Pin degradation is the wearing down of brass pin receptacles within a plug or the pins inside a socket. The microscopic deterioration of these brass pins during coupling and uncoupling can cause the connection between the socket and the plug to become weak over time. Pin degradation also occurs when sodium chloride, calcium chloride, and moisture enter the open plug and socket connection, creating corrosion. Corrosion can be devastating because it wears down the pins much faster, disrupting the connection. Pin corrosion increases the connection resistance, which increases the chances of voltage drop to the lighting, ABS module, and auxiliary.  

Pin Lifespan

The average lifespan of pins depends on what conditions the truck has been operating in and how often drivers are coupling and uncoupling the electrical connections. Pins typically will last between 6-18 months. However, drivers who are coupling and uncoupling their plugs and sockets multiple times a day are likely to experience more frequent pin degradation. 

Drivers operating in locations where the weather is extreme and many road chemicals are used, are more likely to experience higher levels of pin corrosion.  

Mitigating Degradation

Perform routine maintenance checks on plug and socket connection every 3-6 months, or more frequently where conditions contribute to faster deterioration of the pins.

To help prevent corrosion, clean plug and socket connections with a plug and socket brush and electrical cleaner only. The plug and socket must be completely dry after each cleaning before applying dielectric grease to pints and coupling back together. This will help slow down the process of pin degradation due to corrosion. The quality of the pins also plays a role.  

For a quick and temporary solution to pin degradation from prolonged use, spec a split pin socket design. The split pin design allows the pins to spread when the connection between the plug and socket has deteriorated. To keep the plug and socket connection as robust as possible, inserting a screwdriver into the “split-pin” will create a snugger fit between the plug and socket.

When spec’ing sockets, selecting those with split pins will continue to serve as an extended temporary solution. Brass is resistant to corrosion. Be sure to spec 100% brass pins, which will last longer than zinc or brass-plated pins. Remember that brass-plated pins may initially offer some protection, but with continual coupling and uncoupling, the surface will eventually degrade, exposing the material underneath the plating.

Choosing plugs and sockets with anti-corrosive properties such as GFN, composite, or nylon bodies and “plug-in” features reduce downtime and labor costs.

The Phillips Solution

Phillips has designed plug and socket product solutions to help alleviate corrosion and offer quick and easy serviceability relative to pin degradation.  

The Phillips QCS2® (Quick-Change Socket) is a harness system developed to reduce socket replacement time, lowering maintenance costs significantly. A bulleted and non-corrosive weather-proof socket plugs into the harness boot without any re-wiring. The flanged edges of the socket boot envelop and surround the edge of the socket to seal out moisture, further preventing corrosion.  

The QCP™ (Quick-Change Plug) is a weather-proof plug with a replaceable plug cartridge – think disposable razor head. 

Easily replaced pins avoid repair with re-wiring a new plug or replacing the entire assembly. Using a QCP™ is a way to refresh pins quickly, with minimal cost for a cartridge. It also saves time, reducing a repair or replacement from 15-30 minutes down to about 2 minutes.

By spec’ing quality products with anti-corrosive features and performing routine maintenance, the effects pin degradation can be reduced.