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  • Dust, dirt, or grease on electrical contacts can increase electrical resistance and cause connectivity and circuit issues. These problems can affect the ignition’s functionality, which can lead to safety hazards.
  • An electrical contact cleaner is a solvent designed to remove contaminants from electronic components. Compared to most solvent cleaners, electrical contact cleaners can clean surfaces without requiring the user to rub or wipe the component’s surface.
  • Be careful, you should know that electrical contact cleaners are flammable and can cause short circuits. Some contact cleaners can also damage materials like rubber and plastic.

Conductive surfaces, electrical contacts, connectors, and switches can get dirty and contaminated over time. Although on signal circuits that don’t carry current, the mating connectors can look just fine and still impede the voltage needed for an accurate input.

The presence of dust, dirt, or grease can increase electrical resistance and cause connectivity and circuit issues. These problems can affect electronics such as your vehicle’s starter motor, headlights, and fuel pump. This can even be a safety hazard since it can cause your vehicle to stall or lack proper lighting

, Electrical Contact Cleaner Spray: Function, Uses, and Tips

Pro Tips are nuggets of information direct from ASE-certified automobile technicians working with, which may include unique, personal insights based on their years of experience working in the automotive industry. These can help you make more informed decisions about your car.

Pro Tip: On high current circuits, resistance caused by contaminated connectors can cause heat buildup that will destroy the connectors.

Sometimes, dirty contacts can also create patches of high resistance, which can heat up. Fortunately, electrical contact cleaners can allow vehicle owners to clean electronic parts like the ignition easily and prevent these problems from occurring.

What Is an Electrical Contact Cleaner?

An electrical contact cleaner is a solvent designed to remove contaminants from electronic components. Compared to most solvent cleaners, electric contact cleaners can clean surfaces without requiring the user to rub or wipe the component’s surface. As long as the contact cleaner touches the component, it’ll be able to remove contaminants.

Note, however, that you should have enough understanding of connectors in general to know when using an electrical contact cleaner is the appropriate solution.

electrical contact cleaner only works when the connector is not damaged
Electrical contact cleaner only works when the connector isn’t damaged. In the photo, A and C will benefit from electrical Contact cleaning. B and D will need to be replaced. | Image Source: Richard McCuistian

Contact cleaners come in a pressurized aerosol can. Once the nozzle is pressed, the high pressure sprays air and contact cleaner solution in the chosen direction. Cleaning the electrical connectors and switches in tight areas with the nozzle can be difficult. Luckily, most contact cleaners also come with a small hose that you can install at the end of the nozzle, which allows you to accurately spray the contact cleaner into nooks and crannies.

Can You Use a Contact Cleaner on an Ignition Switch?

Your vehicle’s ignition switch is responsible for completing a circuit that activates your vehicle’s starter motor, which then starts the engine. Sometimes, the electrical contacts on the ignition switch can get dirty. When you turn the key, the dirt might create resistance which can prevent the starter motor from activating.

ignition switch connector that does not need electrical contact cleaner
If the ignition switch connector looks like the one in the photo, electrical contact cleaner isn’t the solution. The switch and its connector will both need replacing. | Image Source: Richard McCuistian

Safety Precautions When Using Contact Cleaners

Contact cleaner is convenient and easy to use, but there are some safety precautions that you should know.

Some Contact Cleaners Are Flammable

Electrical contact cleaner sprays contain alcohol and hydrocarbon solvents, which are flammable. Hence, you shouldn’t use contact cleaners near open flames, sparks, or hot surfaces, or on live circuits that may create a spark and ignite the cleaner. Otherwise, the contact cleaner vapors could combust and potentially cause burns or fires.

Contact cleaners should be used in well-ventilated environments to allow the vapors to disperse. Otherwise, your skin and eyes might become irritated because of the solvent’s harsh chemicals.

Contact Cleaners Can Cause a Short Circuit if Not Allowed to Dry

Contact cleaners are rated by their corresponding dielectric strength, which is the maximum amount of current the solvent can withstand before it allows electricity to flow. If a contact cleaner is sprayed onto a circuit that exceeds its dielectric strength, then the solvent will conduct electricity and potentially cause a short circuit.

Caution: Never use electrical contact cleaner on a live circuit where current is flowing.

Contact Cleaner Can Damage Rubber or Plastics

Some contact cleaners that use harsh solvents like toluene, xylene, and acetone can damage rigid plastics like Acrylonitrile Butadiene Styrene (ABS), polycarbonate, and acrylic. The solvents can cause these materials to become brittle and create small cracks. Many gaskets made from rubber and silicone can also be susceptible to these harsh solvents. You should be careful when spraying contact cleaners near these materials. On the other hand, contact cleaners that have alcohol and hydrocarbons for a base tend to be less harsh on these sensitive plastics. If you’re using contact cleaners for electronic components near plastic components, then you should use alcohol and hydrocarbon-based contact cleaners instead.

Electrical contact cleaners offer a convenient and effective way to clean electronic systems. That said, you should always use contact cleaners with caution. Be mindful of safety precautions in order to prevent accidents.

About The Authors
Written By Automotive and Tech Writers

The Research Team is composed of experienced automotive and tech writers working with (ASE)-certified automobile technicians and automotive journalists to bring up-to-date, helpful information to car owners in the US. Guided by's thorough editorial process, our team strives to produce guides and resources DIYers and casual car owners can trust.

Reviewed By Technical Reviewer at

Richard McCuistian has worked for nearly 50 years in the automotive field as a professional technician, an instructor, and a freelance automotive writer for Motor Age, ACtion magazine, Power Stroke Registry, and others. Richard is ASE certified for more than 30 years in 10 categories, including L1 Advanced Engine Performance and Light Vehicle Diesel.

Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.

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