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Mine is wired like Spyerx posted. Works perfectly. I wonder if this is a late model early model 964 difference and the way we used only works on the later MY cars.
Thoughts?
Originally Posted by ToniWonKanobi
I have a 91, but the date on the little gold sticker in the door well says December 90. Not sure if that matters. I removed fuse and tried the Bridge Adapter Relay and the jumper method. Will try the purple wire method today and see if that finally works.
Originally Posted by Spyerx
my car is a 91, the purple wire method is what worked. Remove the relay, tap the purple wire, jump to that relay plug. Make it tidy. Worked for a year, no issues. I do get a no-fan error in the CCU codes though :-) But there is no fan.
Originally Posted by wallra
mine is a 91 put the bridge relay in worked great. no cut wires.
Originally Posted by seeq
I did remove the fuse with both way. Mine is 94.
So I tried all the methods described above (and in other threads), and the only one that worked was tapping into the purple wire and running a lead to the rearward-most female connector thingy on the blower relay platform.
So I tried all the methods described above (and in other threads), and the only one that worked was tapping into the purple wire and running a lead to the rearward-most female connector thingy on the blower relay platform.
Yes this is how my 91 is done! Works great. Ya I had to use one of those crappy blue wire tap things :-(
Just tried this wiring bypass, but the relay control wire feeds into fuse 14 and that fuse blew. The result was no air conditioning on a hot, muggy day. We confirmed it's wired correctly. Any idea why fuse 14 is blowing?
Thanks,
Wired the bypass correctly but lost air conditioning with blown fuse 14
Fuse 14 (serves rear fog light and reverse lights)
Did the blower delete on MY 90 C4 Cab, with A/C. Used the bypass relay, 964-610-184-00, and can confirm that my front fans are working. I also have the violet wire but didn't use this. My mixing servos were non functional but I am part way thru refurbishing them and have heat. Even with the rear blower done and only one frunk flapper open, there is plenty of heat from the stock heat exchangers.
Did the blower delete on MY 90 C4 Cab, with A/C. Used the bypass relay, 964-610-184-00, and can confirm that my front fans are working. I also have the violet wire but didn't use this. My mixing servos were non functional but I am part way thru refurbishing them and have heat. Even with the rear blower done and only one frunk flapper open, there is plenty of heat from the stock heat exchangers.
Good to know that your MY 90 works with the bypass relay method. I'm wondering if I should try the relay method instead of the wire method tried on my MY90 coupe. As noted above, the AC was cutting out with a blown fuse with the wire method. I'd like to get that ten pound blower motor out of the engine bay, but I need the AC.
I'll give the relay a try. If if anyone else can chime in as to why the fuse may be blowing with the wire method, I'd greatly appreciate it.
My car is a 1990 UK C2 manual without air con option.
I have intermittent fan on any heat setting except cold. On cold it works consistently. I can't seem to resolve it. Currently I'm running a switched live from the coil, and have previously tried the cross jumper with the same result.
I looked at doing the mod as per the OP, but my car does not have the violet wire. As per other posts I started looking at the yellow/green, however I have 2 of them one thick, one thin. They both go to the '9 oclock' position where my switched coil jumper plugs in. I'm completely stumped now! Using a meter, there does not seem to be another switched live under there to try. Anyone have a solution?
Hi guys ,
I am taking the opportunity this thread is back as I am quite confused, and my wiring does not make the fans working well at all temperature ...
My car is manufacture in 1992 and I have the AC.
I did the first type wiring suggest by Anto, with the wire going from the + coil to where the relay is with a 5 amp fuse, quite tidy as I manage to have the fuse inside the box,
but the fans only work when the temperature setting is on cold, or sometimes not and sometimes suddenly work ... so its not really working properly,
would anyone had succefully done a wiring on a 92 car with AC, what would be the best way of wiring ? a picture would be great ,
Thank you !
Hey, I'm working on removing the blower. I put in the bridge adapter, disconnected the blower and the fans still work, so that's good. I am wondering what to do with the resistor and temperature sensor that sit in the tube. How can these be disconnected? I've poked around a bit but cannot see where the wires go. The car is '90 C4.
Thanks for any help,
Tore
Just bumping this old thread. Going to try the factory bypass relay on my MY 90 car and wondering if there is also a fuse to be removed (as shown on the 993 fuse box) for our 964s or if just the relay worked for folks?
Just bumping this old thread. Going to try the factory bypass relay on my MY 90 car and wondering if there is also a fuse to be removed (as shown on the 993 fuse box) for our 964s or if just the relay worked for folks?
I’d leave the relay... simply remove the blower, swap the “blower motor” resistor with a simple jumper, and then replace the NTC sensor with a 10k ohm resistor.This will allow the CCU to think everything is normal temp (no need for fan on cool down), but fools it into thinking it’s working those other times (call for heat on start up).
Hi all,
I have a 964 C4 and tried all a.m. wirings without success.
The purple cable solution was my last hope, but I didn't succeed.
Whenever I raise the temp from the blue point the fwd cabin blower shut down
Has anybody an idea?
Sorry for bumping this thread... but for those that delete the blower, what do you do with the connector? Just zip tie it out of the way?
@revolve40 that's exactly what I did when trying to make the bypass work. I first wrapped the connectors in small plastic ziploc bags and electrical tape to seal them off, and then zip-tied to the metal frame that the backside of the blower motor rests in. Sorry for the very delayed response to your question!
Originally Posted by northracer
Hi all,
I have a 964 C4 and tried all a.m. wirings without success.
The purple cable solution was my last hope, but I didn't succeed.
Whenever I raise the temp from the blue point the fwd cabin blower shut down
Has anybody an idea?
Cheers,
Matthias
@northracer what year is your 964? Mine is a MY1991 C2 coupe with a build date of September 11, 1990, and I have never had any success getting the wiring to work with any of the proposed methods. I've read somewhere, but can't remember where, that there was a software update to the CCU somewhere during the MY1991 production, and I've always suspected that maybe I have an older version of the CCU that the wiring bypass doesn't seem to be compatible with. If your car is newer than mine, that shoots that theory down.
In reality, I've gone back to using the rear blower motor, as I like to have working heat when needed, especially when I need to demist/defrost the front windscreen in the rare times it is both cold and humid in Houston. My "butt-dyno" can't tell the difference between with and without the rear blower motor, but my feet can when its cold
hi, thanks for your reply, mine is build in 1989 MY90, with A/C option hence with purple cable.
as soon as the heater flaps open, means temp in cabin is less than the selected one on the temp ****,
the cabin fan shut off.
Maybe you are right and I will re-install the blower again, but somehow it must work, as many of us made it...
04-04-2017, 04:19 PM
