P0645 FORD code

P0645 code definition If your PCM has stored a P0645 code, it means that a problem has been identified in the A/C clutch relay control circuit.

How do I fix code P0645?

How To Correct P0645 A/C Clutch Relay Control Circuit

  1. Replacing the A/C clutch relay.
  2. Replacing blown fuse or fuse-able link (if applicable)
  3. Cleaning corrosion from connectors.
  4. Evacuate and recharge A/C system.
  5. Repairing or replacing wiring.
  6. Repairing or replacing ground straps.
  7. Replacing a control module.

What does code P0645 mean?

a A/C Clutch Relay Control Circuit

OBD-II Code P0645 is defined as a A/C Clutch Relay Control Circuit. The engine control module (PCM) uses a relay to control voltage to the A/C Compressor Clutch. The A/C clutch engages, allowing the Air Conditioning system to operate. When the PCM is unable to control the relay, code P0645 will set.

What does the A C clutch relay do?

The air conditioning clutch relay transfers power, like a switch, from the interior A/C controls of an automobile to the A/C compressor, engaging the compressor clutch. Checking an A/C clutch relay is a process of eliminating possible connection failures.

How do I know if my AC clutch relay is bad?

Common signs include inconsistent cooling, not hearing a click from the compressor turning on, and no cold air.

How can I tell if a relay is bad?


Zitat von Youtube: Out. Sit it down right there take your other relay. Out. Alright and swap them and then see if the problem goes away with your horn see if it blows if it blows then you probably had a bad relay.

What causes AC clutch failure?

Clutch failure is usually caused by high pressure or voltage issues, or a combination of both. Steps to check: 1) Check the refrigerant in the system. With a wrong charge the pressure switches will cause the compressor to constantly engage and disengage.

How much does it cost to replace AC clutch?

The average AC compressor clutch replacement cost is between $700 and $1000. Labor costs tend to be about $150 to $250, with the new compressor costing $450 to $850. It’s not normally recommended to replace the compressor clutch, but rather, install a whole new compressor.

Can you replace AC clutch without removing compressor?

Yes, you can technically replace the clutch without removing the compressor. The reason people suggest doing them together is that when one fails, the other usually isn’t too far behind it. It’s just a matter of convenience to replace them both since you’re already doing most of the same steps anyway.

How do I check my AC compressor clutch?

Zitat von Youtube: In this case black wire is ground and yellow wire is positive using a pointy tip you can supply 12 volts from the battery to the clutch. If the clutch is working properly you should hear and see it.

How do I manually engage my AC compressor clutch?

At the compressor’s front side, unplug the single wire connector, take a jumper wire and attach it to the wire that you just disconnected from the compressor. Connect the other end of the jumper’s wire to the positive terminal of the car battery. This will enable the compressor to start manually.

What are the symptoms of a bad AC compressor?

5 Signs & Symptoms of a Bad AC Compressor

  • Your AC Is Making Growling, Screeching, or Clattering Noises. Electrical failures in the compressor will make your AC emit unusual clunking or rattling noises. …
  • You Have a Hard Time Getting Your AC to Start. …
  • Your AC Stops Blowing Cold Air. …
  • Circuit Breaker Problems. …
  • Diminished Airflow.


How do I know if my AC clutch is working?

Zitat von Youtube: And if it is not spinning that means that it is not engaged now your AC compressor clutch may also cycle on and off so it may spin. And then stop spinning and then spin. And then stop spinning.

How do I fix my AC clutch?

Zitat von Youtube: Off first check to make sure that the clutch turns freely by manually turning it with your. Hand most ac clutches are designed to turn freely when disengaged. If the clutch will not turn freely.

What controls the AC compressor clutch?

Looking at the graph the compressor clutch has a unique relay, it has a compressor control relay that operates in a variety of ways depending upon the application. From the two fuses, one is controlling the coil in the relay (using a 10 amp fuse) that feeds from the relay.

How much is a compressor clutch?

The average cost for AC compressor clutch replacement is between $563 and $613. Labor costs are estimated between $176 and $223 while parts are priced between $387 and $391. This range does not include taxes and fees, and does not factor in your specific vehicle or unique location. Related repairs may also be needed.

What happens if I don’t fix my AC compressor?

If all the refrigerant leaks out, it could cause the unit to overheat. More subtle signs of ac compressor failure include reduced air coming from vents; warm air coming from vents; and a unit that is running virtually constantly. All of which will lead to an increased power bill if the compressor is not repaired.

Is it worth replacing compressor on AC unit in car?

An AC compressor is not a maintenance part which you are expected to regularly replace on some interval. The compressor only needs to be replaced if it fails. They can last the lifetime of the car, but generally a compressor’s life span is around 10-12 years and K miles.

Can I just replace my car AC compressor?

The gas can be cooled by immersing the coil in water or by a fan. Typically, replacing a compressor should be done by a professional, but you can perform this task at home if you are competent working with your hands. Doing the job yourself can also save you a decent amount of money.

How much does it cost to get AC compressor replaced in car?

How Much Does Car A/C Compressor Repair and Replacement Cost? Car a/c compressor replacement costs about $994 for car a/c compressor with average prices of car a/c compressor ranging from $842 for a compressor to $1146 for car a/c compressor in the US for 2020, according to Repairpal.com.

How many miles do AC compressors last?

Air-conditioning compressors often last the life of a vehicle, but they can fail because bearings wear out, seals leak and long-term corrosion takes its toll, plus other factors. If a compressor does need to be replaced, it should be one-and-done, not something that occurs every 50,000 miles.

How much does it cost to change car AC compressor?

The Best in Auto Repair



The average cost for AC compressor replacement is between $812 and $1,041. Labor costs are estimated between $161 and $204 while parts are priced between $651 and $838. This range does not include taxes and fees, and does not factor in your specific vehicle or unique location.

Can I drive my car if the AC compressor is bad?

It is most likely OK to operate your vehicle even thought the a/c compressor has failed. However there are a couple things to be aware of. As long as the compressor pulley is rotating smoothly, without wobble or noise, it shouldn’t affect belt tension or operation of the other belt-driven accessories.

How long does it take to replace car AC compressor?

It entails removing and disposing of any remaining refrigerant, disconnecting and removing the old compressor, installing the new one with proper fittings, and recharging with refrigerant. Add it all up and it typically takes four to six hours.

Can a bad AC compressor cause a car to not start?

A seized a/c compressor can certainly make the engine difficult to start, if not start at all. To describe it in simple terms, the a/c compressor is similar to a mini engine.

What sound does a bad AC compressor make?

So if you turn on your AC and hear a rattle, it may mean you have a failing or bad: AC compressor. Rattling or your car air conditioner making loud humming noises which get worse as you accelerate can both be signs you need to replace your AC compressor.

Can low refrigerant cause AC compressor to not turn on?

Yes, when the refrigerant level drops below the recommended level, AC Compressor may refuse to start. But do not panic because a faulty compressor does not mean the HVAC unit is compromised.