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Undue AC Failures

Generally in all-electric cars climate control system is similar to that of a vehicle with an internal combustion engine except that ICE uses a mechanical compressor driven by the engine through a clutch.

The LEAF, like some hybrid vehicles, uses an electric motor as a compressor. The compressor increases the density, and hence the temperature, of refrigerant gas.

It is then sent through a condenser which extracts and radiates the heat, converting the gas to a liquid state. From there it goes through an expansion valve, which results in it cooling as it returns to a gaseous state before entering the evaporator where it collects heat from air being blown past it.


In the tropics, both EV and ICE undergo premature AC repairs. There can be many causes, will be expensive in some cases. Here are the most common causes.

  • Micro leaks from the connections, O rings etc.
  • Electrical failiures / fauilty sensors
  • Filter drier and expansion valve failiures (if equipped)
  • Deteoration of the evaporator coil

If the evaporator coil is found to be the culprit the cost will be higher! Evaporator coil to last long, as much as the life of the compressor, but it’s not happening, costs are big!

In the case of Nissan Leaf and some other cars, the job is even more extensive as its needing the removal of the entire instrument cluster/dashboard.

The manufacturer wouldn’t have mandated the removal of the instrument cluster to replace the Evaporator coil if they ever expected such a replacement.

As almost everyone in the automobile industry is saying, the future is electric. Like IC engine-powered cars, electric cars are climate-controlled, but instead of using an engine to power the compressor, they use electricity.

Evaporator Failures

We do many bad things that are detrimental to the evaporator. Here are a few key points you may consider in using the AC system in high humid countries, or in the tropics.

​Don’t use poor and fake ​cabin filters. Change the filters as​ and when​ required.

Another blunder, improper fitting of the cabin filter. It’s a tricky mechanism and may tend to bend the filter if not done professionally. So the air may bypass the filter clogging the evaporator.

Ensure the correct side insertion. Some filters are unmarked.

​Do not use additional floor mats​. Especially the rubber mats are not suitable for the cars as these got no static effect to hold the dust. Even 3M type mats are not appropriate in this context as these hide the dirt within. Until you clean these dust bumps up and down when you move, making it fine dust within an enclosed area. This is even more dangerous as we use recirculating air mode only.

​Not to use fabric seat covers which is again bad as these release fine wool.

​Use the Air Conditioner in recirculating mode, as possible but with intermittent good outdoor air.

A precautionary measure, run the blower fast for 5 minutes before you shut the EV/ car in the evening.

At the start, let the blower run for a minute, ideally, windows rolled down to ease up the temperature differences of the evaporator.

Ensure that your system runs on the correct refrigerant pressure, this is to be checked during the scheduled maintenance.

It is advisable to check the compressor status/RPM too during the scheduled maintenance.

Un serviced EV, ruined the Evaporator

Knowing a Filter Failure

First, the airflow becomes poor. And next, in hot weather air conditioning works worse.

Third, in wet weather windows fog up too much. This is another sign of a clogged cabin filter.

Fourth, there can be an unpleasant smell in the cabin dust or mold when turning on the air conditioner.

All of these signs may indicate a clogged Cabin Filter. If at least one of them appears, check the cabin filter and clean/replace it with a new one as necessary. BUT, don’t forget the fitting.

Cabin filters are available for varying quality and prices from LKR 1,500 to LKR 3,400. The topmost is a Carbon activated filter which cuts the road odor too. But you can buy good quality filters for less than LKR 2,000 without Carbon activation which is no use in preventing evaporator. Don’t fall for unbranded and fakes, ensure your seller is reliable.

Improper fitting – ruined the evaporator.
Inferior / poor filters

Premature replacements of evaporator coil (cooler) or other components are not a problem of the car it is purely a problem of the usage and somewhat on the operating conditions as well​.

However, a proper diagnosis procedure is required to ascertain the cause of the failure as removal of the instrument cluster should be the last resort.

New / Replacement Evaporator Coil

Remember, the Evaporator coil is destined to last long as the life of the compressor, let’s make it happen to avoid heavy replacement costs! Also, the modifications to the tubing are not acceptable during a replacement. Ensure that you get at least a one-year warranty too.

Evaporator coil replacement to be done with various other component checks and services as we cannot leave any room for re-removal. Atop usual leak checks, o ring replacements, etc, comprehensive servicing of the blower compartment and the ducts are mandatory during an evaporator replacement.

The entire process with the qualified technical team of GoEV is estimated at LKR 39,500. (with a Leaf specific replacement evaporator) which includes a one-year warranty on the parts and the workmanship.

Also available Made in Japan genuine used Evaporators. Prices are based on the age of the salvaged car. 2014/15 – 45,000. 2016/2017 – 48,500. 2017/2020 – 55,000 (from ZE1)

Read on preventive service here:


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