Will fitting an aftermarket alarm affect my manufacturer warranty?

In most cases, no. A professionally installed aftermarket car security system, fitted by a qualified auto electrician using correct wiring methods, should not affect your manufacturer's warranty. We can advise on your specific vehicle before any work is carried out.

Which systems will my insurer actually accept?

Most mainstream UK insurers require Thatcham-approved products — specifically Category 1 or Category 2 ratings. We only supply and fit insurance-approved vehicle security systems, and we can check your insurer's specific requirements before recommending a product.

My car has keyless entry. Do I need a ghost immobiliser?

It is strongly worth considering. Relay attacks are now among the most common methods used by car thieves in the UK, and keyless entry vehicles are directly targeted. A ghost or OBD immobiliser effectively blocks this type of attack by requiring a PIN sequence that criminals cannot replicate, even if they intercept your key signal.

How long does installation take?

A standard alarm or immobiliser installation typically takes between two and four hours. More complex packages involving multiple systems, tracker integration, or ECU coding may take a full day. We will give you a realistic time estimate when you book.

Do you cover the whole of Sheffield?

Our workshop is based in Sheffield and we serve customers across the city and the wider South Yorkshire area. Contact us to confirm coverage for your location, particularly if you are interested in a mobile installation.

What’s the difference between a car alarm and an immobiliser?

A car alarm is designed to deter theft by triggering a loud siren when unauthorised access is detected, drawing attention to the vehicle. An immobiliser works differently by preventing the engine from starting unless the correct key or authorised signal is present. Most modern security setups use both systems together for layered protection.

Will adding a security system drain my car battery?

Properly installed alarm and immobiliser systems are designed to use very minimal power when the vehicle is parked. They enter a low-energy standby mode and should not noticeably affect your battery. Issues only tend to occur when systems are poorly fitted or incorrectly wired.

Can I upgrade or add to an existing car security system?

Yes, existing factory-fitted or aftermarket systems can often be upgraded. Many vehicles allow additional layers such as enhanced immobilisers, trackers, or more advanced alarm sensors to be integrated without replacing the original setup completely.

What does Thatcham approval actually mean for vehicle security?

Thatcham-approved systems have been independently tested to meet strict UK insurance industry standards for effectiveness and reliability. In simple terms, it means the device has been proven to reduce theft risk and is widely recognised by insurers as a trusted form of protection.

Why do some vehicles still get stolen even with security systems fitted?

No system is completely unbreakable. Theft usually occurs when security is outdated, poorly installed, or not suited to the vehicle’s risk level. Criminal methods also evolve, which is why using professionally fitted, modern security systems significantly improves protection compared to basic factory security alone.

Car Alarm &

Immobiliser

Installation

Sheffield

If you're looking for reliable, professionally fitted car alarm and immobiliser installation in Sheffield, OJB Autocare is your local specialist. We provide a full range of vehicle security systems for all makes and models — from Thatcham-approved alarms to ghost immobilisers and insurance-accepted security packages. Whether you're concerned about rising vehicle crime in South Yorkshire or simply want the peace of mind that comes with properly protected wheels, our team is here to help.

Car Alarm &

Immobiliser

Installation

Services

OJB Autocare provides the full range of car alarm and immobiliser installation in Sheffield, tailored to your vehicle, your budget, and your insurer's requirements.

The gold standard of aftermarket car security. A Cat 1 system combines a full alarm — including perimeter, interior, and shock sensors — with electronic immobilisation. It is the most widely accepted system by UK insurers and provides the highest level of deterrence for most vehicles.
Learn More: Car Alarm & Immobiliser Installation Leeds
A standalone electronic immobiliser that prevents the engine from starting without the correct authorisation signal. Ideal for vehicles that already have a factory alarm but lack effective immobilisation, or as a supplementary layer of protection.
One of the most effective responses to the relay attack epidemic. A ghost immobiliser is hidden within the vehicle's wiring and requires the driver to enter a silent PIN sequence — using existing buttons on the steering wheel or dashboard — before the car will start. There is nothing for a criminal to find, remove, or bypass. Widely accepted by specialist and mainstream insurers alike.
Where a stolen vehicle needs to be recoverable as well as protected, we fit GPS tracking devices alongside security systems. Subscription-based tracker services provide 24-hour monitoring and have strong recovery rates when activated quickly.

The Installation

Process

Getting your vehicle properly secured at OJB Autocare is a simple, five-step process.

Step 1 — Free Consultation

Step 2 — Clear, Itemised Quote

Step 3 — Book Your Appointment

Step 4 — Professional Fitting

Step 5 — Documentation and Handover

Why Choose OJB Autocare in

Sheffield

OJB Autocare stands out as a trusted choice for vehicle security in Sheffield because we are truly local, with a clear understanding of the area, the vehicles people drive, and the real security risks they face. We specialise in auto electrical work, meaning vehicle security isn’t a side service—it’s our expertise. We only install Thatcham-approved or insurance-accepted systems, ensuring your protection is both effective and recognised by insurers. Every installation is carried out with care, with properly routed wiring, full system testing, and clear documentation provided. Above all, we keep things simple and honest, offering straightforward advice, transparent pricing, and no unnecessary upselling.

Why Vehicle Security Matters

in Sheffield

Vehicle crime remains a concern across South Yorkshire, with increasingly sophisticated theft methods such as relay attacks—where thieves clone keyless entry signals—now common. Cars with keyless systems, especially those made after 2015, are particularly vulnerable without added protection. In areas like Hillsborough, Walkley, and Woodseats, even everyday vehicles are regularly targeted, not just high-end models. Installing a proper security system significantly reduces your risk, as thieves often avoid well-protected cars. There’s also a financial benefit, as many insurers offer lower premiums for vehicles fitted with approved security systems, helping offset the cost while providing long-term peace of mind.

Frequently Asked Questions

In most cases, no. A professionally installed aftermarket car security system, fitted by a qualified auto electrician using correct wiring methods, should not affect your manufacturer's warranty. We can advise on your specific vehicle before any work is carried out.
Most mainstream UK insurers require Thatcham-approved products — specifically Category 1 or Category 2 ratings. We only supply and fit insurance-approved vehicle security systems, and we can check your insurer's specific requirements before recommending a product.
It is strongly worth considering. Relay attacks are now among the most common methods used by car thieves in the UK, and keyless entry vehicles are directly targeted. A ghost or OBD immobiliser effectively blocks this type of attack by requiring a PIN sequence that criminals cannot replicate, even if they intercept your key signal.
A car alarm is designed to deter theft by triggering a loud siren when unauthorised access is detected, drawing attention to the vehicle. An immobiliser works differently by preventing the engine from starting unless the correct key or authorised signal is present. Most modern security setups use both systems together for layered protection.
Properly installed alarm and immobiliser systems are designed to use very minimal power when the vehicle is parked. They enter a low-energy standby mode and should not noticeably affect your battery. Issues only tend to occur when systems are poorly fitted or incorrectly wired.

A standard alarm or immobiliser installation typically takes between two and four hours. More complex packages involving multiple systems, tracker integration, or ECU coding may take a full day. We will give you a realistic time estimate when you book.
Our workshop is based in Sheffield and we serve customers across the city and the wider South Yorkshire area. Contact us to confirm coverage for your location, particularly if you are interested in a mobile installation.
Yes, existing factory-fitted or aftermarket systems can often be upgraded. Many vehicles allow additional layers such as enhanced immobilisers, trackers, or more advanced alarm sensors to be integrated without replacing the original setup completely.
Thatcham-approved systems have been independently tested to meet strict UK insurance industry standards for effectiveness and reliability. In simple terms, it means the device has been proven to reduce theft risk and is widely recognised by insurers as a trusted form of protection.
No system is completely unbreakable. Theft usually occurs when security is outdated, poorly installed, or not suited to the vehicle’s risk level. Criminal methods also evolve, which is why using professionally fitted, modern security systems significantly improves protection compared to basic factory security alone.

Contact us.

For more information about all our vehicle security products and services, drop us an email using this form, or send us a WhatsApp message. Thanks, OJB.