John McM

I seem to be missing something here. Is there a start to finish DIY guide for a '90 model? The link given seems to carry on from another thread.

DobermanDad

Right here is what you want:
https://rennlist.com/forums/964-foru...-solution.html

LPMM

Bought mine from Sunset, part# 993.211.941.00

tdiquattro

If you dont have aircon you can just link between the 2 relay sockets. very easy,

porsche mania

I used the fix in the first link. My car is a 1990 model and it worked perfectly, is totally reversible and its virtually free! As far as I was aware it's the same on all cars, just the colour of the wire used differs on later models.

Spyerx

cool thanks guys. off to electronic store to get a few quick connects and some jumper wire....

FlyinTomato

mines 92. the fuse box looks just like the pic. in option 1.




perhaps option 2 is for 993s only? I actually bought the bridge plug. Will the plug still work instead of the wire mod?

Mezger

Oh thanks for the PN, actually I wasn't aware that there is a factory part available.
But at a price tag twice as high as the after market carbon parts I rather get one of those.
Satin black paint is cheap...

Mezger

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greaser5

Finished this up today using the factory RS bypass tube. Took about 30 minutes using the "definitive method" mentioned above. Thanks for the help guys.

pcolony

I have a 1993, I bought the Porsche relay (964.610.184.00) to try that method first.

As a test, before I pulled out the stock blower and install the RS bypass, I installed the relay (with the car off, immediately the fan started blowing), and pulled the 30 amp fuse (fan stops blowing). I then started up the car and adjusted the A/C to see if I had fan control at all temps. It didn't work as expected... the air only blew hard on full-cold temp setting. If I changed the temp setting to anything but full cold, the fan speed was very low. I swapped back in the 30 amp fuse and stock relay, and all back to normal.

Now I'm thinking, should I just do the tap purple wire method? Or should A/C have really worked properly with the Porsche relay (964.610.184.00) and 30 amp fuse pulled?

Any tips or advise appreciated!

Thanks!

LPMM

pcolony

With the 30 amp fuse back in, the blower stays on constantly, even if the key isn't in the ignition. I just tested how the A/C works with the new relay installed + the 30 amp fuse installed... Generally A/C and heat works, but fan speed fluctuates in weird random ways when adjusting the temp dial, which does not happen with the stock relay installed.

rkwfxd

90 964 C2 here. I spent like $20 for the relay. It was plug and play. A/C and everything else works fine. Blower is gone and I have RS tube.

gregmitch

My 91 C4 came with the heater blower bypass already installed and it didn't have the jumper wire or relay. The fans worked, but the windshield defroster would shut off after a few seconds when activated. Installed the bridge relay (964-610-184-00) and now everything works perfectly...except for the lack of air coming out of the passenger side vents, but that's a whole different issue.