I took my '00 Neon in for a A/C diagnosis. The initial diagnosis was that the system is charged, has pressure, but won't kick on due to an electrical problem. He had said that he unplugged the low pressure switch and still wasn't getting any cold air. Meanwhile he also observed that there was a crack in the radiator on the top on the stamp. He said it would be easier to diagnose further if he replaced the radiator. I promptly JB welded the crack until I can afford the labor costs to replace the radiator.

The mechanic pointed out a connector that wasn't plugged into anything. I noticed that there is a plug on the compressor, but it has something connected to it already. Does anyone know what it goes to? I included a picture outlining the plug and the relation to the compressor.

Also: Does $200 for labor sound right? It includes the price of the coolant that is added, but not the part. I already bought the radiator.

 

Another question. THe radiator I bought has the integrated transmission cooler, but I have a manual transmission. Is that a problem? I believe the MTX models don't come with, nor do they need a transmission cooler.

 

I don't see a problem with your radiator having the transmission cooler mounted to it, even though you don't use it.
Just leave it, remove it, or cover the two ports with something.
Check with the stores to see if they have a radiator that does not included with the transmission cooler for your car. You may save money on that.

 

You should have brought your car to a more trusted shop. I mean a shop that advertised for AC recharging and diagnosis. They are more professional at this.

As for the radiator. I don't see why you need to replace it if you only want to fix your air conditioner to get cold air.

If you mean the AC condenser then it need to be replaced if there is it's leak. A leak is usually occur there. It let your refrigerant out so the system never fully charged. The shop should be able to tell if there is a leak. The AC condenser look just like the radiator. It's mounted to the radiator but in the front. Both units get air coming in from the vents (in the front of the car).

There is an easy way to check the low pressure switch, and the high pressure switch to see if they went bad. If that is not a problem then it could be the bad compressor clutch or the clutch relay.

Right now you need to tell us if the compressor is compressing air at all, so we can help you more.

Just take your car to another shop, because it seem like the shop doing your car doesn't know how to fix this. They even recommended you to replace an expensive part (the radiator) just to get this fixed.

 

I think it shouldn't take them longer than 2 hours to replace the radiator. It's more like 1 hour job.

at my area:
1 hour labor is $70-$90

Check coolant for price.

 

There IS a crack in the radiator, and it IS letting out coolant. JB weld didn't hold it. The AC system has pressure. He said that it was indeed an electrical problem, as I also suspected this back at my hometown repair shop.

 

If the radiator is cracked then it need to be replaced, but I'm just saying that the radiator doesn't need to be replaced in other for the shop to further diagnosis your AC.

The AC clutch will only kick in if the system has some refrigerant. I say at least 45 psi static pressure.

Every time the AC clutch kick in, you can hear a "clicking" noise.
When that happens, look at the center of the compressor pulley to see if it's spinning:
-If it's spinning then your compressor is working (it's compressing air).
-If it's not spinning then your AC clutch need to be replaced.

If the clutch doesn't kick in at all. You don't hear a "clicking" noise right at the moment you turned on your AC, to full blast, and with the engine is running then you need to figure out why it's not doing so.

Check for the low pressure switch, high pressure switch, the clutch relay, and a few other things.

Like I said "there is an easy way to check the pressure switch by connect the two pins with a paper clip or wire".

If you AC is short cycling then it's still low on refrigerant.
If everything is working then the low side pressure should be steady at 32-38 psi when the AC is on, and the engine is running.

 

When the engine is running and the AC is full blast, the PSI isn't even measurable. The gauge goes to the other side, passed the highest mark on there. I'm assuming the AC clutch is out. I'll be taking it to a different shop to get that looked at. The mechanic tried the low pressure switch trick and still couldn't get it to kick on.

I got my radiator replaced, and it looks a lot sturdier than the crap stock radiator I had on it.

 

The new shop should be able to fix it.

Good luck with getting your AC fixed.

 

sometimes when a mechanic fools around with the radiator they will bang up the connection to the a/c clutch. I've done it a few times where I have to solder in new leads with heavier wires. Took me forever to figure it out then I remembered the a/c clutch will click randomly when the engine in running... it ran for 5 minutes no click so I new where to look next starting from the a/c clutch connector... I takes a lot for an a/c clutch to wear out, mine has 200k+ on it and I run the a/c 90% of the time with this car.... but like everyone says look/think for the simple things, connectors, grounds, cold beers


what a relief that was it was 119 degrees last summer in Dallas O.o