@002 Dodge Dakota 4.7l a/c relay tests good but will not engage compressor clutch. All wiring looks good power to pin 30 and power to pin 85 with ignition on. continuity to compressor clutch, ground on compressor clutch good.

 

Pressure transducer is new and operating correctly. When I remove the relay and jump from pin 30 to pin 86 a/c works great. Swapped relays and no difference.

 

What do your pressures look like?

 

What would pressures have to do with the problem? I'm having the same issue. Fuse and relay are good but clutch still won't engage

 

I just read the other thread on A/C and learned a lot. Quick question. Not trying to hijack your thread Michel111, but we might have the same issues. After reading that thread, I'm considering just starting from ground zero on my a/c situation. When I bought the truck the a/c didn't work. Compressor was there, clutch was locked up and the previous owner had the belt routed bypassing the compressor. Also, a/c clutch fuse under the hood was blown. Money is tight so the other I bought a compressor from a junkyard. I had many vehicles to choose from because there were a lot of Dakotas and Durangos on the lot. I found a Durango that had a real nice interior and some febreze clip on things in the vents so it looked promising that the a/c was working before the vehicle went down. I got the compressor and took it home and installed it and also installed a new fuse.

At the time I did not know about having to add the pag 100 oil to the system. I did the simple add a can of r-134 and hope it worked. Well the compressor never kicked on. What I'm wanting to do now is check this orifice for what is referred to is signs of the "black death". I don't know what that is, but it sounds bad. Where is it located and how do I remove it? I'm also wanting to evacuate the system again and pull a vacuum on it, then add my oil and my refrigerant. I'm thinking there's a good chance my "new" compressor is ok, what I'm worried about is my trucks system. With the compressor frozen and a/c clutch fuse blown, I'm very suspicious.

Last question. With my truck not having a/c for a while, is it possible, the dryer or any other parts in the a/c system went bad?

 

OK I don't like answering A/C questions as its a tricky and complicated thing that most don't get.

Also 2002 and up they made many changes to the A/C system that confuse even me.

You should find your orifice tube by following the output of the condenser it should loop up then down in the engine bay look for a fat connector thats it.

All black death is is when the A/C system burns up due to lack of oil (pag 100) this leaves a black mess in all the A/C system this black mess needs to be cleaned out before you fix the A/C. Replacing as much of the A/C system is usually the best way to fix black death.

The orifice tube is confusing because its a tube with an orifice in it checking it can be hard as usually the orifice gets pushed far inside the tube high pressure air or water is needed to push it out most just replace the tube with a new one with a new orifice inside it. The reason it gets pushed deep in the tube is the high pressure its under as much as 300 + psi.

Confusing yes

 

This may help this is an orifice tube or liquid A/C line.




This is an orifice that's inside the tube.

 

Ok, seems pretty straight forward. After watching some youtube videos last night i think I need to replace my accumulator. Sounds like the accumulator/dryer has a moisture absorbing chemical in it and if it's left open to the atmosphere for a while it's bad for it. I was surprised I could not find many videos on adding the Pag oil. I found one where he added a liquid into the low side of his compressor when he was installing it. What I'm wondering is if I use one of the charge cans of pag oil and charge it into the low side when I'm adding my refrigerant, does the oil flow through the system and then stay in the compressor? I don't want to burn up my compressor.

 

Oil circulates with the refrigerant. So, if you get r134 with oil in it..... you supposedly don't need to add additional oil. Trouble with that is, you aren't sure just exactly how much oil ends up in the system..... I much prefer to add the right amount of oil to the system, then recharge it......

 

The oil flows through the system and yes replace the accumulator/dryer. Oil will be in every part of the system it moves with the R-134. One of the last A/C posts I had I have an oil chart that shows how much oil is in each part of the system 7 to 8 oz. total is good.

Knowing how much oil to ad is a hard one their is no easy answer the chart gives a solid possible answer but it can vary.

If you replace the accumulator/dryer and drain all the oil out of the compressor then only 3 oz. of oil will remain in the system. So what I do is ad 2 oz. of oil directly in the low side of the compressor before you install it so now you are around 2 oz. short at 5 oz. The last needed oil I use one oil charge can before the R-134 I like the oil charge because it contains an extra coolant booster called ICE 32.

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