[Alg]

I have a 99 Dakota 3.9 L XLT. 10 years ago I had the entire AC system changed out at a shop. Five years ago it quit working again. I took it to the same shop and they said I needed a compressor. They gave me a report showing it has failed. Since I don’t use the AC very much I simply bypasssd the compressor. Well now I’m not tolerating the heat so well so I’ve thought about replacing the compressor. Spending 1200 bucks to change the compressor that I can buy for less than a couple hundred seems a waste. My issue is that I cannot find anywhere that shows exactly what I have in this truck. I just can’t tell what is where. I know that the compressor is bad. But I just don’t know how to proceed from here. the clutch is working cycling real fast. I have read and watched videos related to this but am stumped. Any help/input is appreciated.
Thanks.

 

[9t9-5.2]

Generally the clutch repeatedly cycling, is a sign the system is low on refrigerant. Five years on a lightly used compressor seems odd that it would be bad, but anything is possible.
Compressor prices can vary greatly. Shops usually charge full MSRP for parts even though they buy them at a lower cost than you can buy at. It adds to their bottom line. Additionally labor rates vary greatly.
Post the report they gave you. Maybe some under hood pics also.

What do you mean "My issue is that I cannot find anywhere that shows exactly what I have in this truck. I just can’t tell what is where."

 

[Alg]

Not much report. Just a note that says compressor failed. I have traced the lines to the firewall. I don’t see any type accumulator between the condenser and the firewall. In the picture, this circled thing is immediately outside the firewall on return to compressor(the low pressure side). So if it is an accumulator I guess I have an expansion valve, but have no idea where the damn thing is. If it’s under the dash I think I’m screwed. I would like to see a diagram of the ac system that is in this truck, but haven’t managed to find one Anyone able to clarify some of this please ?

 

[AandPDan]

The canister that you have circled is the accumulator.
You don't have an expansion valve. The Dakota uses a fixed orifice tube that performs the same function. It's in the line from the compressor outlet to the evaporator.
The evaporator is under the dash. The condenser is in front of the radiator. Those 4 items, and the compressor, make up the a/c system.

I'm going on 20 years with the original compressor, almost 200k miles.

As 9t9 says, rapid cycling usually means low on refrigerant.

Finding a leak can be difficult but a good "sniffer" can help - if there is any refrigerant. To recharge the system, ideally, you'd fully evacuate the system and then recharge it by weight, on a sticker under the hood. If the system can't maintain a vacuum, which boils off any moisture in the system, then you have a leak that needs to be repaired. If the system has been exposed to the atmosphere then the accumulator should be replaced.

Ask the shop what the pressures are.

 

[Alg]

The canister that you have circled is the accumulator.
You don't have an expansion valve. The Dakota uses a fixed orifice tube that performs the same function. It's in the line from the compressor outlet to the evaporator.
The evaporator is under the dash. The condenser is in front of the radiator. Those 4 items, and the compressor, make up the a/c system.

I'm going on 20 years with the original compressor, almost 200k miles.

As 9t9 says, rapid cycling usually means low on refrigerant.

Finding a leak can be difficult but a good "sniffer" can help - if there is any refrigerant. To recharge the system, ideally, you'd fully evacuate the system and then recharge it by weight, on a sticker under the hood. If the system can't maintain a vacuum, which boils off any moisture in the system, then you have a leak that needs to be repaired. If the system has been exposed to the atmosphere then the accumulator should be replaced.

Ask the shop what the pressures are.

Thanks! Exactly where should I expect to find the orifice tube? From what I think you are saying it isn’t under the dash?

Thanks again.

 

[AandPDan]

Typo in the prior post. The orifice tube is in the line from the CONDENSER outlet to the evaporator inlet. Follow the line and you should see a joint. That's where it is.

 

[Alg]

Thanks. So it’s in the engine compartment and not under the dash I suppose. There is at least one joint in that run.

 

[alexcklie]

I have a 99 Dakota 3.9 L XLT. 10 years ago I had the entire AC system changed out at a shop. Five years ago it quit working again. I took it to the same shop and they said I needed a compressor. They gave me a report showing it has failed. Since I don’t use the AC very much I simply bypasssd the compressor. Well now I’m not tolerating the heat so well so I’ve thought about replacing the compressor. Spending 1200 bucks to change the compressor that I can buy for less than a couple hundred seems a waste. My issue is that I cannot find anywhere that shows exactly what I have in this truck. I just can’t tell what is where. I know that the compressor is bad. But I just don’t know how to proceed from here. the clutch is working cycling real fast. I have read and watched videos related to this but am stumped. Any help/input is appreciated.
Thanks.

You can do it yourself

I have a 99 Dakota 3.9 L XLT. 10 years ago I had the entire AC system changed out at a shop. Five years ago it quit working again. I took it to the same shop and they said I needed a compressor. They gave me a report showing it has failed. Since I don’t use the AC very much I simply bypasssd the compressor. Well now I’m not tolerating the heat so well so I’ve thought about replacing the compressor. Spending 1200 bucks to change the compressor that I can buy for less than a couple hundred seems a waste. My issue is that I cannot find anywhere that shows exactly what I have in this truck. I just can’t tell what is where. I know that the compressor is bad. But I just don’t know how to proceed from here. the clutch is working cycling real fast. I have read and watched videos related to this but am stumped. Any help/input is appreciated.
Thanks.

It is not a big deal; you can do it yourself.
However, you have not given enough information to provide you with a more straightforward answer.

The first important step is that you determine if you have any refrigerant leaks on the system.

If your compressor failed with loud noises, the chances are that you have a leak in the system, and the oil escaped. First, you have to make sure that there is no refrigerant under pressure in the system, then you can remove the compressor, remove the oil plug, and measure how much oil is inside the compressor. If empty or almost no oil, you will know why your compressor failed.

Have you overcharged the system? The excess of refrigerant will result in liquid refrigerant returning to the compressor, it will increase the pressure, and the liquid refrigerant will damage the valves. Also, the liquid refrigerant will reduce the ability of the oil to lubricate the internals of the compressor. Oil is diluted in liquid refrigerant

Is the evaporator coil clogged? The liquid refrigerant will not evaporate and will return as such to the compressor.

Is the expansion device filter clogged, you have to remove it and inspect it, if clogged then you will have to clean the lines before installing a new compressor.

There are plenty of videos that can give you information on how to find a leak and the tools that you need to do the job. However, you can do an initial inspection where you check for oil on hoses, refrigerant lines, condenser coil, compressor expansion orifice /valves, and the liquid receiver or suction accumulator. Checking for leaks in the evaporator is much more complicated and will require you a leak detector.

Removing the evaporator on a Dakota / Durango is a big job that requires you to remove the dashboard entirely. There is a video for that on youtube for Durango in which they replace the core heater (basically is the same headache for the evaporator)

Go to Four Seasons | English read all technician resources

 

[Alg]

You can do it yourself

It is not a big deal; you can do it yourself.
However, you have not given enough information to provide you with a more straightforward answer.

The first important step is that you determine if you have any refrigerant leaks on the system.

If your compressor failed with loud noises, the chances are that you have a leak in the system, and the oil escaped. First, you have to make sure that there is no refrigerant under pressure in the system, then you can remove the compressor, remove the oil plug, and measure how much oil is inside the compressor. If empty or almost no oil, you will know why your compressor failed.

Have you overcharged the system? The excess of refrigerant will result in liquid refrigerant returning to the compressor, it will increase the pressure, and the liquid refrigerant will damage the valves. Also, the liquid refrigerant will reduce the ability of the oil to lubricate the internals of the compressor. Oil is diluted in liquid refrigerant

Is the evaporator coil clogged? The liquid refrigerant will not evaporate and will return as such to the compressor.

Is the expansion device filter clogged, you have to remove it and inspect it, if clogged then you will have to clean the lines before installing a new compressor.

There are plenty of videos that can give you information on how to find a leak and the tools that you need to do the job. However, you can do an initial inspection where you check for oil on hoses, refrigerant lines, condenser coil, compressor expansion orifice /valves, and the liquid receiver or suction accumulator. Checking for leaks in the evaporator is much more complicated and will require you a leak detector.

Removing the evaporator on a Dakota / Durango is a big job that requires you to remove the dashboard entirely. There is a video for that on youtube for Durango in which they replace the core heater (basically is the same headache for the evaporator)

Go to Four Seasons | English read all technician resources

Thanks for the input. The compressor failed years ago. I don’t remember how long. But it was within three or four years after the entire system, including the evaporator, was replaced. I don’t remember what exactly occurred at the time it failed, but I took it to the shop where the original work was done and was told the compressor failed. At the time I really didn’t use the ac and did t want to spend the money so I left it as is. Well now I don’t tolerate the heat so am forced to address. There is refrigerant in the system. I have a set of gauges. I plan to see if readings have changed any since I took readings last week. I bypassed the compressor when it failed and replaced the belt last week. I took readings then. I haven’t used the ac since because it’s not cooling and the clutch screams bloody murder when engaged. It didn’t when I bypassed the compressor. If the readings are lower I’ll have to decide how to check it for leaks. I can’t decide which is best. I’ve watched videos about checking for leaks. I really need to determine if I have a leak under the dash. I think I can handle work under the hood, but honestly I have no interest in pulling the entire dash. I welcome comments and input. Thanks.

 

[Alg]

Thanks for the input. The compressor failed years ago. I don’t remember how long. But it was within three or four years after the entire system, including the evaporator, was replaced. I don’t remember what exactly occurred at the time it failed, but I took it to the shop where the original work was done and was told the compressor failed. At the time I really didn’t use the ac and did t want to spend the money so I left it as is. Well now I don’t tolerate the heat so am forced to address. There is refrigerant in the system. I have a set of gauges. I plan to see if readings have changed any since I took readings last week. I bypassed the compressor when it failed and replaced the belt last week. I took readings then. I haven’t used the ac since because it’s not cooling and the clutch screams bloody murder when engaged. It didn’t when I bypassed the compressor. If the readings are lower I’ll have to decide how to check it for leaks. I can’t decide which is best. I’ve watched videos about checking for leaks. I really need to determine if I have a leak under the dash. I think I can handle work under the hood, but honestly I have no interest in pulling the entire dash. I welcome comments and input. Thanks.

 

[RalphP]

IF you're rebuilding the system anyway, and will replace the accumulator / receiver-dryer, AND don't mind flushing the lines ... you can always use an air compressor to pressurize the system to find leaks with the old "squirt bottle with soapy water" trick ( cheapest car wash you can buy, mix about 50/50 with water, in a pump type squirt bottle ...)

I'd also recommend putting a water remover (like one sold to go with paint guns) in the air line to charge the A/C lines with.

What the pros use is usually nitrogen since it's completely water free in the tanks.

RwP

 

[alexcklie]

IF you're rebuilding the system anyway, and will replace the accumulator / receiver-dryer, AND don't mind flushing the lines ... you can always use an air compressor to pressurize the system to find leaks with the old "squirt bottle with soapy water" trick ( cheapest car wash you can buy, mix about 50/50 with water, in a pump type squirt bottle ...)

I'd also recommend putting a water remover (like one sold to go with paint guns) in the air line to charge the A/C lines with.

What the pros use is usually nitrogen since it's completely water free in the tanks.

RwP

Are you serious about that advice?

Read a book about HVAC before posting that advice.

Never pressurize with air form an air compressor, You will introduce humidity in the system, and the only way to remove moisture is a vacuum pump. Only specific solvents will work to clear HVAC.

Vacuum pumps reduce the pressure in the system, and droplets of water evaporate (moisture that has condensed on the pipes, evaporator, condenser and other components) are removed in the form of vapor from the system. Also, flushing with refrigerant does not remove moisture that condensates in the pipes, Air Conditioning Vacuum Pump

 

[RalphP]

a) If you're rebuilding anyway,

b) and will replace the receiver/dryer and/or accumulator,

c) and will flush the lines afterwards ...

Yep, if it's the last step before you rebuild ... you can pressure test it with compressed air.

Nitrogen is the gas of choice of HVAC professionals, but with dry enough air, air's good.

AS LONG AS YOU'RE REBUILDING IT, WILL SWAP THE RECEIVER/DRYER OR ACCUMLATOR, AND WILL FLUSH THE LINES AFTERWARDS.

How else do you find leaks? When you suck it down with the vacuum pump and it won't hold?

And yes, I've read several books about HVAC operation.

That's why I had the caveats there, BTW.

RwP