wilko

Just prefer to let those who know what they,re doing tamper with my prized possession , I,d be in tears if I broke something meddling.
Think I,l wait until service in a few weeks to have it looked at

boxsey911

Doing the blue dot/red dot routine with the CCU is not tinkering or doing any harm. We would really like to hear what you find

milutintin

Hi,

I've removed the Relays and checked these things:

R04 - Oil Cooler Fan Relay
30-87C - Fan works in slow mode
30-87 - Fan works in fast mode

R14 - AC Fan Realy
30-87C - Fan doesnt start (ac ballast resistor is kaput)
30-87 - Fan works in fast mode

Rear Blower relay (engine compartment)
30-87c - Fan works in slow mode
30-87 - Fan works in fast mode

So apparently all the fan's in the system are near ok and there is no reason for the CCU to be dead on this part of the system.

I'll check the servos manually to see if they're working ok.

Any help?

Thanks

milutintin

I also discovered that I also have this part 96410640302 broken:


https://rennlist.com/forums/964-foru...ine-cover.html

How does this part affect the heating system?

Dsqr964

More "cooler" air will be mixed in with the air coming from the engine to the cabin. Not sure but might allow a few more fumes in from the engine compartment but there I am not too sure as I am still chasing some fuel smells. -D²

wilko

LOL , thanks boxsey , can manage to twiddle some ***** but as a general rule when it comes to cars i avoid jobs that require anything other than my fingers to carry out ,
anyway , ,did the hot=cold thing with ignition half turned , ,no noise at the rear but front fan worked again along with the button for screen de-mist , 30/40 seconds then nothing ????

milutintin

I've diagnosed my problem. Previous owner modified the power supply to the HVAC system so it only gets 12v when switched. The new power supply was fused behind the fuse box and the fuse was blown. Only way to find out was to remove the fuse box and then change the fuse. Now I'm going back to the original configuration to identify what was the problem. Maybe it was the battery draining problem due to the CCU fan (https://rennlist.com/forums/964-foru...-opinions.html).

wilko

boxsey , just got round to opening the fusebox in engine compartment & it was the 30a fuse that had blown ,
happy days & thanks for interest & replies

boxsey911

Welcome to the DIY club Wilko

swftiii

Bringing this thread back as I'm now dealing with a similar issue and am hoping to get some guidance:

Problem: Fuse #1 (25) under the bonnet has blown a few times over the last month causing the ccu and cabin fans up front to stop working

Symptoms I've noticed:
1. When this occured originally (a few drives ago), I checked the rear heater fan operation using the ***** on the ccu method and it was operating as expected
2. I replaced Fuse #1 and all worked well for a few drives, then it blew again today (by coincidence both times it has blown while driving it was raining - not hard)
3. When the cabin fans are working, they don't seem to operate below fan speed setting '2', but seem to work fine once the setting is above that. I could put the fan to 3 or 4 and then bring it down to less than 2 and it would work for a while at that lower setting before slowing way down and requiring the fan selector to go above 2 again.
4. Driver front fan had made some squeeking noises a while back, but that seems to have gone away since the weather has cooled off and I've started driving the car more often.

Ideas and ways to diagnose please let me know,

Thanks,

-Skip