From your description of the symptoms, it sounds like you don't have enough cool airflow going thru the radiator & A/C condenser with that specific V-mount setup, especially when the car isn't moving at speed. With the A/C on, the condenser is adding extra heat to the cool air flow that is supposed to be going thru the radiator to keep water temps in check, hence the higher water temps you're seeing with the A/C on - that would concern me more than the A/C performance. I'd guess the A/C doesn't cool the cabin as well as it should under those conditions as well?

Can't really tell from that one picture of your V-mount setup, but here's a few ideas to throw out there:

Ducting & Fans - Cool air from outside needs to be directed & ducted to go thru all the heat exchangers and not have a path to sneak around them. From the picture, looks like those black areas to the sides of the condenser/radiator are allowing air to sneak around the sides? That would not be a good thing. Do you know with any certainty how much air the Spal fans are pulling thru the heat exchangers with the car sitting still? Do you have control of what temps the fans come on, and can you do multiple speeds with them like the OEM setup? If you do, you might consider having the fans come on at a lower temperature and/or run at a higher speed when the A/C is on

 

i have had a very similar issue with my vmount setup. I am not an hvac expert by any means but my issue was a clogged dryer.
they are pretty cheap to replace but you need to vacuum and recharge the system

 

This might be also the case for me at least partially. I did discover a mess of small seeds of some sort. Maybe a rodent got into the car behind the dash.
I believe there is a cooler behind the dash or by under the glove box that would need to be cleaned?

All valid points. I'm going to address the ducting and see what improvements I get. Then move on from there. Thanks!

 

Check out @JP3 Motorsports youtube. They show how to clean everything:

I agree with Pete (though, I'm no expert). I think your condenser is just heatsoaking your radiator when A/C is on. Look into how the condenser is mounted in the Greddy Vmount configuration. Admittedly, it's not the BEST solution, and does not cool the cabin as well when stationary, but you don't have the drawbacks of a situation like yours. For me personally, this is a better solution than risking heatsoaking the rad. You can also search through some of the Greddy threads and see how some people have tacked the issue of low airflow over the condenser at a stop.

 

Thanks! Good insight. I'll do a little more digging. Also I'm going to drum up a spacer to lift the condenser off of the radiator and see what that does too.

 

While I do some testing, has anyone just changed out the AC compressor clutch? It seems like mine is making a noise.

 

has anyone just changed out the AC compressor clutch? It seems like mine is making a noise.

 

I know it's possible to remove & replace the clutch, because I had to do that step to rebuild a used FD compressor that I have, though I just reused my old clutch. Not sure where your could buy a new clutch though, as I've yet to see anyone that sells just the clutch - I've only seen new or rebuilt compressors for sale that include the clutch. Before thinking about replacing your clutch though, check the simple stuff first - could be noisy because the belt tension is too tight/loose or the pulleys/belts may be slightly misaligned.

 

Unfortunately it's not the belt. It's a clear noise when the clutch is engaged. It's been difficult in finding the clutch itself. I really don't want to go through drain the system to change the compressor if I don't have to.

 

It’s relatively easy to change just the clutch. I don’t know where you could buy a new one, but you could buy a used compressor and remove the clutch off of there. Replacing it without evacuating the system. When you take the clutch apart, it’s normally the abrasive material strip is worn down, which is normal after years of use. As a test you can put 12v to clutch and turn by hand to see if you have it slipping there or hear any weird noise. If the abrasive material isn’t worn down too bad, you may be able to remove a few shims to tighten up the spacing and get you thru. If you do put a different clutch on there, you will have to shim it to work correctly. After re-building one of those compressors, I found the stack height would change some and an adjustment to the clutch was needed.


~ GW

 

Yes I've don't endless searching for the clutch itself and no luck. I did find one that was identical but the plug was different.

 

Change the plug. The oem grounds out to the case and receives a 12v + on the one connection point at the harness.


~ GW

 

OK I'll check it out. Wasn't sure on the connection at the compressor because of how it's wired. It jumps from one place to another then to the plug.
​​​​​
​

 

In the stock form, it leaves the magnetic clutch with two wires. One of the wires grounds to the compressor case. The other goes through a temperature switch on the top of the compressor, and then out to the harness where it receives 12v to engage the clutch. Post a picture of the new clutch assembly and plug. You may not even need to change the magnet at all if it’s an identical assembly.


~ GW


> Adding photos of the wiring.

 

Greatly appreciate the picture. I'll post an image of what I have later this evening.

 

 

Hard to tell depth comparison from the photo. Looks correct. I would try to leave the existing magnet and use the new pieces. Make sure to check that the clutch is shimmed correctly after you install it. I would use whatever shims came with the new unit first. Worst case would be having to make an adjustment to the existing harness if you have to use the new magnet, which won’t be too bad.

~ GW

 

I appreciate it. I'll start with the clutch only and take it from there.

 

If it works out, do post a link to where you bought the assembly from. It could help future searchers.


~ GW