CCU delete and fans

Subscribe
Aug 1, 2021 | 04:37 AM
  #1  
Hello Everyone

On my 964 3.8 RS replica ( C2 base car and 993 engine and electronics ) the aircon and ventilation system was deleted before I bought it.

The car is built to be used on track but I don t know exactley what was deleted completely and what was kept on the car.

When I worked on the dashboard area I removed the CCU unit ( not sure if it s a 993 or 964 version ) and noticed that the faceplate itself could easely be separated from the heavier electronic part so as anyway nothing was working I kept it disconnected and only fitted the face part for the look.

But I read on the forums that some oil cooler and maybe other fans should be connected to the CCU to work or should be modified.

I would like more details on how to check if the different fans are fitted on the car and working and eventually details on how to make eventual modifications.

I could of course fit back and connect the complete CCU but I don t know if originally it was makingthe fans work or not.

Thanks for any picture or link

Reply 0
Aug 1, 2021 | 08:37 AM
  #2  
Have these things been removed: the HVAC suitcase, the heat blower from the engine, and the ac condenser fan? If so, you would be left with the oil cooler fan in the front right. Did they switch to a front oil cooler or dual oil cooler with no fan? You possibly might not have any electric fans that need controlled!

Reply 0
Aug 1, 2021 | 04:13 PM
  #3  
All CCU functions are described here:
https://www.bergvillfx.com/categorie...system-details
Cheers,
Tore
Reply 0
Aug 2, 2021 | 01:19 AM
  #4  
Quote: Have these things been removed: the HVAC suitcase, the heat blower from the engine, and the ac condenser fan? If so, you would be left with the oil cooler fan in the front right. Did they switch to a front oil cooler or dual oil cooler with no fan? You possibly might not have any electric fans that need controlled!
The Heat blower from the engine is removed as well as the A/C compressor and the car is using an aftermarket exhaust with racing manifolds so no heater related parts there.

I don't know if the HVAC suitcase was removed I will look

There still is the oil cooler with it s fan in the front right ( I still have to check if there is a second one fitted ) but I don t know if the fan of that oil cooler is actually working or if it was working when the CCU was still connected.

Any easy way to see if the fan is working?

ToreB thanks for the link

Reply 0
Aug 2, 2021 | 07:44 AM
  #5  
The CCU originally controls the 2 speeds of the fan. The PO/builder might’ve set it up differently (i.e. external controller, temp relay, etc…). Go for a drive and see if it kicks on!

You can manually jump the original relay and see if the fan and resistor are functional. Check this link: https://rennlist.com/forums/964-foru...test-plan.html

I’ve decided to separate the control from CCU. Sourced a brushless fan and a config PWM controller that works off the OEM temp sensor. Just waiting on some waterjet for the shroud. Might be an alternative for you.




Reply 0
Aug 2, 2021 | 10:12 AM
  #6  
Thanks a lot for your reply

The HVAC suitcase is still on the car but as mentioned before the ventilation never worked even when I left the CCU connected...

I did not know that on the 964 the CCU was really a part of the system to make other stuff work I tought it was just there for the ventilation and A/C...

So now I will look at the oil cooler fan to see if it works ( BTW if the fan doesn t work is there a big difference in oil temperature? especially on traffic? )

but I m also wondering... If I would still have a working CCU and HVAC suitcase should I have any ventilation work even if the engine blower was removed?

The previous owner made a nice car and the engine is built by a reputable tuner that probably did excellent work but I could not get much info on some not working electrical things ( ABS not working but no warning light, central locking not working at all, and no ventilation ) and to make things more complicated

it s a mix of 993 engine and ECM and 964 parts

Reply 0
Aug 2, 2021 | 01:57 PM
  #7  
Quote: BTW if the fan doesn t work is there a big difference in oil temperature? especially on traffic?
At a standstill with the engine running, you need a fan on the oem oil cooler (just as they designed it). My engine doesn't like oil temps above 10pm

Quote: I m also wondering... If I would still have a working CCU and HVAC suitcase should I have any ventilation work even if the engine blower was removed?
I currently have the CCU only controlling the suitcase (no AC, no engine blower)
Reply 0
Aug 3, 2021 | 10:18 PM
  #8  
For what it's worth, I deleted the CCU on my MY 1990 C2, and deleted the fan on the oil cooler as well. I also deleted the HVAC suitcase. Even in light traffic, the temps stay below 9 on the gauge.

A gridlock in a summer swelter would not do so well, but air cooled engines don't like to sit in traffic.
Reply 0

Rennlist Stories

The Best Porsche Posts for Porsche Enthusiasts

Explore
story-0

10 Best Non-Flat Six Porsches You Can Buy For Under $100K

 Joe Kucinski
story-1

Porsche's Top 5 Most Questionable Naming Decisions

 Verdad Gallardo
story-2

Pogea Racing's 964 Porsche 911 Reimagination Stands Out in a Crowded Field

 Verdad Gallardo
story-3

6 Convertible Top MYTHS Most People Don't Understand!

 Michael S. Palmer
story-4

2026 Porsche 911 Club Coupe is Spectacular, And Everything Wrong with the Porsche Market

 Joe Kucinski
story-5

Talos Takes Your 991 Porsche 911 GT3 to the Next Level for a Cool $1.13 Million

 Verdad Gallardo
story-6

9 Vehicles Porsche Helped Engineer that Aren't Porsches

 Verdad Gallardo
story-7

9 Features and Characteristics That Only Porsche People Understand

 Verdad Gallardo
story-8

I've Written 500 Rennlist Articles: Here's How Porsche Has Changed Along the Way

 Joe Kucinski
story-9

10 Most Unnecessary Porsches Ever Built (And Why We Love Them)

 Verdad Gallardo
Subscribe
story-0

10 Best Non-Flat Six Porsches You Can Buy For Under $100K

Slideshow: If you have $100K to spend on a Porsche but want something a little different, these are the 10 best non-flat six Porsches you can buy.

By Joe Kucinski | 2026-05-28 15:36:11


VIEW MORE
story-1

Porsche's Top 5 Most Questionable Naming Decisions

Slideshow: For a company obsessed with engineering precision, Porsche has occasionally named its cars in ways that left even loyal enthusiasts scratching their heads.

By Verdad Gallardo | 2026-05-27 18:43:48


VIEW MORE
story-2

Pogea Racing's 964 Porsche 911 Reimagination Stands Out in a Crowded Field

Slideshow: Pogea Racing's latest Porsche 964 project blends carbon-fiber construction, modern chassis upgrades, and up to 500 horsepower while keeping the air-cooled 911 experience firmly analog.

By Verdad Gallardo | 2026-05-23 10:34:27


VIEW MORE
story-3

6 Convertible Top MYTHS Most People Don't Understand!

Slideshow: dispelling common convertible top myths

By Michael S. Palmer | 2026-04-03 00:00:00


VIEW MORE
story-4

2026 Porsche 911 Club Coupe is Spectacular, And Everything Wrong with the Porsche Market

Slideshow: The 2026 Porsche 911 Club Coupe is being resold $150K above sticker and that is a real problem.

By Joe Kucinski | 2026-05-21 11:52:54


VIEW MORE
story-5

Talos Takes Your 991 Porsche 911 GT3 to the Next Level for a Cool $1.13 Million

Slideshow: Talos Vehicles has transformed the Porsche 911 GT3 RS into a carbon-bodied, race-inspired machine that costs well over $1 million before the donor car is even included.

By Verdad Gallardo | 2026-05-19 13:39:04


VIEW MORE
story-6

9 Vehicles Porsche Helped Engineer that Aren't Porsches

Slideshow: Long before engineering consulting became trendy, Porsche was quietly helping other automakers build everything from supercars to economy hatchbacks.

By Verdad Gallardo | 2026-05-15 12:44:44


VIEW MORE
story-7

9 Features and Characteristics That Only Porsche People Understand

Slideshow: Some brands build cars. Porsche builds traditions, obsessions, and a few habits that stopped making sense decades ago but somehow became part of the charm.

By Verdad Gallardo | 2026-05-13 18:46:13


VIEW MORE
story-8

I've Written 500 Rennlist Articles: Here's How Porsche Has Changed Along the Way

Slideshow: Six years and 500 Rennlist articles later, these are the biggest changes at Porsche.

By Joe Kucinski | 2026-05-11 09:52:55


VIEW MORE
story-9

10 Most Unnecessary Porsches Ever Built (And Why We Love Them)

Slideshow: Some Porsches exist for very specific reasons-others feel like they were built just to see if anyone would notice.

By Verdad Gallardo | 2026-05-06 18:00:32


VIEW MORE