MG Comet & Windsor EV AC Issues: Fixes & Costs

If you own an MG Comet or MG Windsor and the cabin still feels warm after ten minutes of driving in May, you are not imagining it and you are not alone. Across Indian cities where the mercury crosses 44 degrees Celsius and a parked car can hit 60 degrees inside within minutes, the air-conditioning system is the single hardest-working component in any EV after the battery. When it underperforms, owners notice immediately, and they search for answers.

Both the MG Comet and the MG Windsor are among India's most popular electric cars, and both run a fully electric, high-voltage air-conditioning system that behaves quite differently from the belt-driven AC in a petrol or diesel car. That difference is the root of most confusion. An EV AC compressor does not spin off the engine, so the way it cools, how fast it cools, and what can go wrong all follow a different rulebook.

This guide is written for the real-world owner whose AC is weak, not cooling at all, blowing warm air, making strange noises, smelling musty, or quietly eating into driving range. We will walk through the symptoms owners actually report, what causes each one, how a proper professional diagnosis is done, which checks you can safely do yourself, when you must call a professional because of the high-voltage compressor, the honest repair-versus-replace picture with indicative Indian rupee costs, and how warranty cover typically works on these MG models.

If you would rather skip straight to a fix, you can book an EV AC service with a doorstep technician. Otherwise, read on so you understand exactly what is happening inside your car.

Why EV AC matters so much in Indian heat

In a petrol car, the AC compressor is bolted to the engine and turns whenever the engine turns. There is enormous mechanical reserve, so the system tends to blow cold fast and hard. In an EV like the Comet or Windsor, the compressor is a high-voltage electric scroll unit driven by its own brushless motor and powered straight from the traction battery. The carmaker tunes how aggressively it runs, because every watt the compressor draws is a watt that could have driven the wheels.

That trade-off is deliberate and it is why EV owners across brands, not just MG, report that cooling feels gentler or slower to arrive than they were used to. The Windsor in particular has a large, airy cabin and a big fixed glass roof, which looks fantastic but soaks up a lot of heat. Several owner reviews note that when the car is parked in direct sun, the AC takes noticeably longer to bring the cabin down to a comfortable temperature, while the same car parked in shade cools without complaint. The Comet, despite its tiny footprint, has also been observed to struggle on bright, high-sun days.

None of this automatically means your car is faulty. But it does mean the line between normal EV behaviour and a genuine fault is blurrier than most owners expect, so knowing what is normal is the first step to fixing what is not.

Common air-conditioning and climate control problems owners report

Here are the symptoms that bring Comet and Windsor owners looking for help, roughly in order of how often they come up.

• Weak or slow cooling. The air is cool but never truly cold, or the cabin takes far too long to come down after the car has been baking in the sun. This is the most common complaint and often the least serious.
• AC blows warm or ambient air. The fan runs but the air is room temperature or warmer. This is a bigger red flag and usually points to refrigerant, the compressor, or an electrical fault rather than tuning.
• Cooling only at higher fan speeds or only while moving. The AC feels fine on the highway but goes weak in slow traffic or at idle in a parking lot. This pattern often points to airflow or condenser issues.
• Intermittent cooling that drops out. Cold air that suddenly turns warm for a while and then returns. Owners of MG electric cars have reported the compressor briefly going offline or shutting off prematurely in hot conditions.
• Strange noises when the AC is on. A hiss, rattle, buzz, or whine that appears only when cooling is engaged. Some noise is normal from an electric compressor and the cooling fans, but new or loud noises deserve attention.
• Bad smells from the vents. A musty, damp, or sour smell when you first switch the AC on, caused by microbial growth on the cooling coil, very common in humid Indian conditions.
• Noticeable range drop with AC on. The predicted range falls sharply the moment cooling is switched on, beyond the modest reduction that is normal for any EV.
• Uneven cooling front to rear. Front occupants are comfortable while rear passengers feel warm, an airflow and cabin-volume issue rather than a system failure, especially in the roomier Windsor.

A single car can show more than one of these at once, and the right fix depends entirely on which symptom you are actually dealing with.

What causes these problems

Most AC complaints on the Comet and Windsor trace back to one of six areas. Several are made worse by the specific conditions Indian cars live in, namely extreme heat, fine road dust, and high humidity.

The high-voltage electric compressor

The compressor is the heart of the system. In these EVs it is an inverter-driven scroll compressor running on the high-voltage bus and varying its own speed to match cooling demand. When it underperforms, you can get weak cooling, warm air, or intermittent dropouts. Because it is electrically driven, faults can be mechanical (internal wear, bearing noise) or electronic (the inverter, control signal, or high-voltage supply). Extreme under-bonnet heat in Indian summers adds thermal stress, and some MG electric cars have been reported to take the compressor offline temporarily when conditions get very hot, which the system does to protect itself.

Refrigerant level and leaks

If the refrigerant charge is low, cooling fades or disappears entirely. The Comet and Windsor, like most modern EVs, use R1234yf refrigerant, which is different from the older R134a used in many petrol cars. A slow leak from a hose, O-ring, condenser, or the compressor seal will gradually starve the system. Vibration from Indian roads and heat cycling can loosen fittings over time. This is one of the most common reasons an AC that worked fine last summer feels weak this summer.

The blower motor and airflow

Even with perfect cooling, you need enough air moving across the coil and into the cabin. A weak or failing blower motor, a blockage, or a fault in the climate control electronics can leave you with cold-but-feeble airflow. If your AC only cools properly at the highest fan settings, airflow is a prime suspect.

The cabin air filter

This is the single most under-appreciated cause of weak cooling, and the easiest to fix. The cabin (pollen) filter sits in the airflow path, and in dusty Indian conditions it clogs far faster than in cleaner climates. A choked filter throttles airflow, makes the AC feel weak, raises energy use, and can trap moisture that turns into the musty smell owners complain about. Many cars come back to life with nothing more than a fresh filter.

The condenser and cooling fans

The condenser at the front of the car dumps heat from the refrigerant to the outside air, helped by electric fans. In India it collects bugs, dust, mud, and plastic-bag debris, which insulates it and kills its efficiency, especially in slow traffic when there is no natural airflow. A clogged condenser, or a fan that is not spinning, classically produces AC that cools on the move but goes warm when you stop. Dust is the enemy here.

Software, settings, and drive modes

Not every weak-cooling complaint is a hardware fault. Eco and Eco+ drive modes deliberately limit how hard the AC compressor works to protect range, so the same car can cool noticeably better in Normal mode than in Eco. MG owners of other models have found that simply switching out of Eco mode restores strong, icy cooling within seconds. There are also genuine software bugs and electrical gremlins to consider, including reports across MG's EV range of HVAC failing because of a fuse problem. A software update or recalibration at the service centre sometimes resolves intermittent climate behaviour without any parts being changed.

How the problem is diagnosed

A proper diagnosis is methodical, and a good technician will not simply top up gas and send you away. Here is what a thorough professional assessment looks like.

1. Confirm the symptom and the conditions. The technician establishes whether the problem is constant or intermittent, sun versus shade, idle versus moving, and which drive mode and AC settings were in use. This alone rules out a lot.
2. Check settings and software first. Drive mode, recirculation, target temperature, and any pending software updates or stored fault codes are reviewed before anyone touches the refrigerant. On these MG cars, the diagnostic scanner reads climate-system error codes directly.
3. Inspect the cabin filter and airflow. The filter is pulled and inspected, and airflow at the vents is checked across fan speeds. A clogged filter is confirmed or cleared early because it is cheap and common.
4. Inspect the condenser and fans. The front condenser is checked for dust and debris and the cooling fans are confirmed to be running when the AC is on.
5. Measure the refrigerant system. Using gauges on the correct R1234yf service ports, the technician reads high and low side pressures to judge whether the charge is correct, low, or overfilled, and whether the compressor is building pressure as it should.
6. Leak detection if pressures are low. If refrigerant is down, the system is checked for leaks using UV dye, an electronic sniffer, or nitrogen pressure testing, so the leak is found and fixed rather than just refilled.
7. Assess the compressor. The compressor is evaluated for correct operation, noise, current draw, and whether its inverter and high-voltage feed are healthy. This is the most specialised part of the job because it involves the high-voltage system.
8. Verify the fix. After any repair, vent temperature is measured with the car running to confirm the cabin is actually reaching the expected cold output.

If you want to understand your car's overall electrical health before booking, ev.care also offers a free EV charging diagnostic tool that can surface related high-voltage and energy-flow concerns worth mentioning to your technician.

Safe DIY checks versus when to call a professional

There is a small set of genuinely safe checks any owner can do, and a hard line beyond which you should stop. Respect that line, because an EV AC system is tied into the high-voltage circuit.

Checks you can safely do yourself

• Switch out of Eco or Eco+ mode. Put the car in Normal mode, set the temperature to the lowest, fan high, and see whether cooling improves within a minute. This is the first thing to try and it costs nothing.
• Use recirculation, not fresh air. On a hot day, recirculation cools far faster because the system is chilling already-cool cabin air instead of pulling in 45-degree outside air.
• Pre-cool the car before you drive. Both the Comet and Windsor support remote climate control through the MG i-SMART app, so you can start cooling while the car is still plugged in or parked. Pre-cooling a heat-soaked cabin while connected to a charger is the single most effective comfort and range trick, because it does not eat into your driving battery.
• Park in shade and crack the windows briefly. Letting trapped super-heated air escape for thirty seconds before you start the AC dramatically shortens cool-down time.
• Inspect and replace the cabin air filter. On these MG cars the cabin filter is owner-serviceable, and a clean replacement is the highest-value DIY fix. If yours is grey, clogged, or smells, swap it.
• Gently clear the front condenser of leaves and visible debris. A soft brush or low-pressure rinse of loose dirt is fine. Do not jam anything into the fins.
• Run the fan-only mode for a couple of minutes before shutting down. Drying the coil after a long drive reduces the musty smell over time.

When to stop and call a professional

Call a qualified EV technician, and do not attempt the job yourself, if any of the following apply.

• The AC blows warm even in Normal mode with a clean filter, which points to refrigerant or the compressor.
• You suspect low gas. Do not buy a DIY top-up can. These EVs use R1234yf, not R134a, and using the wrong refrigerant or oil can damage the system and void cover. Charging also needs proper recovery and vacuum equipment.
• There is any new loud noise, hissing, or burning smell when the AC runs.
• The compressor itself is suspected. The AC compressor on an EV sits on the high-voltage system, with orange high-voltage cabling, and must only be touched by a trained technician. Working on it without proper high-voltage isolation training is genuinely dangerous and can be fatal.
• A dashboard warning light or climate fault message has appeared.

In short, settings, filters, and surface cleaning are fair game. Anything involving refrigerant or the high-voltage compressor is a professional job, full stop.

Repair versus replace, with indicative INR costs

The right call depends entirely on what the diagnosis finds. The figures below are indicative Indian market ranges for guidance only. Actual prices vary by city, by whether the part is genuine MG or aftermarket, by labour rates, and by your warranty status, so always confirm a written estimate first.

• Cabin air filter replacement. Roughly 600 to 2,500 rupees depending on whether you use a genuine or aftermarket filter and whether you do it yourself. Almost always worth doing, not replacing the whole system around it.
• AC system deep clean and anti-bacterial treatment for smells. Roughly 1,200 to 3,000 rupees. The right fix for a musty or sour smell, far cheaper than replacing the coil.
• Condenser cleaning or pressure wash. Roughly 400 to 1,500 rupees. The right first step for cool-on-the-move, warm-at-idle complaints before considering parts.
• Refrigerant leak detection and recharge with R1234yf. Roughly 3,500 to 8,000 rupees for the gas and labour, higher than older R134a cars because the refrigerant itself is more expensive. If a leak is found, the leaking O-ring, hose, or fitting must be repaired too, which adds cost.
• Blower motor replacement. Roughly 4,000 to 12,000 rupees depending on part source and labour.
• Cooling fan or fan motor replacement. Roughly 3,000 to 10,000 rupees.
• Condenser replacement. Roughly 8,000 to 20,000 rupees with parts and labour.
• Evaporator or cooling coil replacement. Roughly 8,000 to 25,000 rupees, higher because it is labour-intensive to access behind the dashboard.
• High-voltage AC compressor replacement. This is the big one, commonly in the range of 30,000 to well over 70,000 rupees with parts and labour, depending on the model and whether a genuine compressor is used. Because of this cost, a compressor is repaired or recovered rather than replaced where possible, and warranty cover matters enormously.

The general rule is simple. Filters, cleaning, leak repair, and recharges are repair-first jobs that are almost always cheaper than replacement and should be tried before condemning major parts. Replacement of a condenser, coil, or compressor is only justified once a diagnosis proves the part has genuinely failed and cannot be repaired. Beware of any shop that jumps straight to compressor replacement without a proper pressure test and leak check first.

Warranty, and how to claim

Warranty is where being methodical really pays off, because a major AC component replaced under cover can save you tens of thousands of rupees.

MG sells the Windsor and Comet in India with a comprehensive vehicle warranty of 3 years and unlimited kilometres covering the car other than the high-voltage battery, and the high-voltage battery itself carries its own long-term cover, with the Windsor notably offering a lifetime battery warranty for the original owner and an 8-year or 160,000 km battery warranty that transfers to a second owner. Specific terms, inclusions, and timelines change over time and by variant, so always check your own car's warranty booklet and current MG policy.

For the AC, the practical points to remember are these.

• The AC compressor, condenser, blower, and related components are typically covered as part of the standard vehicle warranty as manufacturing defects, not as wear items, within the warranty period. That is why a failed compressor inside cover is so much less painful financially.
• Refrigerant top-ups, cabin filters, and cleaning are usually treated as maintenance or consumables and are generally not covered, the same way oil changes are excluded on a petrol car.
• To keep cover valid, follow the scheduled service intervals and keep records. Warranty terms commonly exclude damage caused by missed servicing, unauthorised repairs, or use of non-approved parts and refrigerant, which is another reason not to attempt a DIY gas refill.

To claim, report the fault to an authorised MG service centre while the car is still in warranty, ask them to log the diagnosis and fault codes in writing, and confirm before any work begins whether the repair is being done under warranty or charged to you. Keep every job card and invoice. If a component is borderline, a documented diagnosis from the start strengthens your case.

How ev.care helps

ev.care is built for exactly this situation, the owner who wants the problem understood and fixed properly without guesswork or a wasted trip to a crowded service centre.

• Doorstep diagnosis. A technician comes to you, assesses the symptom in the real conditions your car lives in, and runs a structured check of settings, filter, airflow, condenser, refrigerant pressures, and compressor health rather than blindly refilling gas.
• DIYguru-certified technicians. EV air-conditioning work touches the high-voltage system, so it should only be done by people trained for it. ev.care technicians are DIYguru-certified, which means they are equipped to handle high-voltage components safely and correctly.
• Any brand, any EV. While this guide focuses on the MG Comet and Windsor, the same diagnostic approach applies across electric cars, so you can use ev.care whatever you drive.
• Honest repair-first advice. The goal is to fix the cheapest correct thing first, the filter, the clean, the leak, before ever talking about replacing a major part, and to tell you clearly when something genuinely is covered under warranty.

When you are ready, you can book an EV AC service and have a certified technician look at your car. If your concern is broader than cooling, ev.care also handles EV charging repair & service and offers the free EV charging diagnostic tool to check the wider high-voltage and energy system.

For related reading, see our guide on EV battery thermal management and safety in India, which explains how cooling and the battery interact in extreme heat, and if you also notice charging niggles, common EV slow charging causes and fixes is a useful companion. Owners cross-shopping other popular models may also find our write-up on Tata Nexon EV charging problems helpful for context.

Frequently asked questions

Why does my MG Windsor AC take so long to cool the cabin?

The Windsor has a large cabin and a big fixed glass roof, both of which absorb and hold a lot of heat when the car is parked in the sun. Combined with an electric compressor that is tuned to balance cooling against range, this means cool-down is gentler than you may be used to in a petrol car. Try Normal mode instead of Eco, switch on recirculation, and most importantly pre-cool the car using the i-SMART app while it is still plugged in. If it still blows warm with a clean cabin filter, have the refrigerant and compressor checked, because that is no longer normal behaviour.

Is weak cooling in my MG Comet a fault, or just how it is?

On very bright, high-sun days the Comet's AC can struggle to keep up, and that is a known characteristic rather than necessarily a defect. The honest test is whether it cools acceptably in shade or with pre-cooling and Normal mode. If it cools fine in those conditions but struggles only in extreme direct sun, it is likely behaving as designed. If it blows warm air regardless of conditions, get it diagnosed.

Can I just refill the AC gas myself with a can from the shop?

No. The Comet and Windsor use R1234yf refrigerant, not the older R134a found in many petrol cars, and using the wrong refrigerant or oil can damage the system and void your warranty. Proper recharging also needs recovery and vacuum equipment to remove old gas and moisture first, and if the charge was low there is almost certainly a leak that must be found and fixed rather than just topped up. This is a job for a trained technician.

Why does my AC cool on the highway but go warm in traffic?

This classic pattern usually means the condenser at the front of the car is clogged with dust and debris, or a cooling fan is not running. On the move, natural airflow keeps the condenser working, but at idle it relies on the fans, and if those are blocked or faulty the system cannot shed heat. A condenser clean is cheap and is the right first step before considering any part replacement.

Why does my EV's AC make the range drop so much?

Some range reduction with AC on is completely normal for any EV, because the compressor draws power straight from the traction battery. If the drop seems excessive, it is often made worse by cooling a heat-soaked cabin from scratch on the move. Pre-cooling while plugged in, using recirculation, and parking in shade all reduce the load dramatically. If the range hit is sudden and severe alongside weak cooling, have the system checked, because a struggling compressor works harder and uses more energy.

Is it safe for a technician to work on the EV AC compressor?

Only a properly trained one. The AC compressor on an EV is powered by the high-voltage system, identifiable by its orange high-voltage cabling, and working on it without correct isolation training is genuinely dangerous. This is exactly why ev.care uses DIYguru-certified technicians who are equipped to handle high-voltage components safely. Surface tasks like changing the cabin filter or cleaning the condenser are fine for owners, but anything touching the compressor or refrigerant should be left to a professional.