Heater bypass wiring - which way is best?
#17
#20
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.
#21
Rennlist Member
cool thanks guys. off to electronic store to get a few quick connects and some jumper wire....
#22
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?
perhaps option 2 is for 993s only? I actually bought the bridge plug. Will the plug still work instead of the wire mod?
#23
Instructor
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...
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...
#26
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!
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!
#27
Drifting
I had the same on my 1991 with the relay method and fuse out, the fans only worked on full cold. With the relay method and fuse in, the fans now work at the lowest and highest temperature setting but not in between, which I think is normal but ?
#28
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.
#30
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.