Notices
964 Forum 1989-1994
Sponsored by:
Sponsored by:

Heater bypass wiring - which way is best?

Thread Tools
 
Search this Thread
 
Old 01-07-2016, 10:29 AM
  #1  
greaser5
Rennlist Member
Thread Starter
 
greaser5's Avatar
 
Join Date: Mar 2013
Posts: 144
Received 3 Likes on 3 Posts
Default Heater bypass wiring - which way is best?

So, my heater blower motor in the engine bay is making the dreaded noise and it's time to add a bypass. In doing so, I still want heat... So I need to make some wiring changes. While searching I found two ways:

1. A homegrown method described as "definitive" as found here:

https://rennlist.com/forums/964-foru...-solution.html

OR:

2. Add a bridge relay (964.610.184.00) and then pull the fuse as described here:

https://rennlist.com/forums/993-foru...l#post10404484

Option 2 seems cleaner to me and I'd like use it... But will this retain my heater? Anyone done this?

Thanks,

Ryan
Old 01-07-2016, 11:04 AM
  #2  
DobermanDad
Drifting
 
DobermanDad's Avatar
 
Join Date: Dec 2014
Location: Michigan
Posts: 2,128
Received 6 Likes on 6 Posts
Default

Depends on the year of your car. The first method is for 89 - 90.
Old 01-07-2016, 11:15 AM
  #3  
crg53
Rennlist Member
 
crg53's Avatar
 
Join Date: Jan 2007
Location: Vancouver Island, BC , Canada
Posts: 2,380
Received 13 Likes on 11 Posts
Default

Originally Posted by DobermanDad
Depends on the year of your car. The first method is for 89 - 90.
Not true. I have that set up on my 91, it works perfectly.
Old 01-07-2016, 11:16 AM
  #4  
greaser5
Rennlist Member
Thread Starter
 
greaser5's Avatar
 
Join Date: Mar 2013
Posts: 144
Received 3 Likes on 3 Posts
Default

I have a 90... and now, I'm even more confused as to what to do!
Old 01-07-2016, 12:25 PM
  #5  
DobermanDad
Drifting
 
DobermanDad's Avatar
 
Join Date: Dec 2014
Location: Michigan
Posts: 2,128
Received 6 Likes on 6 Posts
Default

As far as I can remember the early model 964s (89 - 90, someone correct me if I'm wrong) don't have the easier wiring options the later models do. So, the jumper method won't work on the early 964s.

You would need to do the "definitive" method because you have a 90. I have an 89, and that method worked for me. The job is kinda a PITA because there's not a lot of room to work, even if it is just splicing a wire, I could barely get my hands in there. Long pliers would help.

If you have a later 964, why would you go through all that extra work if all you had to do was simply remove the relay and put in or jumper or better yet just plug in another relay?
Old 01-07-2016, 12:42 PM
  #6  
greaser5
Rennlist Member
Thread Starter
 
greaser5's Avatar
 
Join Date: Mar 2013
Posts: 144
Received 3 Likes on 3 Posts
Default

Originally Posted by DobermanDad
As far as I can remember the early model 964s (89 - 90, someone correct me if I'm wrong) don't have the easier wiring options the later models do. So, the jumper method won't work on the early 964s.

You would need to do the "definitive" method because you have a 90. I have an 89, and that method worked for me. The job is kinda a PITA because there's not a lot of room to work, even if it is just splicing a wire, I could barely get my hands in there. Long pliers would help.

If you have a later 964, why would you go through all that extra work if all you had to do was simply remove the relay and put in or jumper or better yet just plug in another relay?
Roger that. Thank you sir.
Old 01-07-2016, 01:30 PM
  #7  
JasonAndreas
Technical Guru
Rennlist Member

 
JasonAndreas's Avatar
 
Join Date: May 2002
Location: USVI
Posts: 8,138
Received 112 Likes on 90 Posts
Default

Originally Posted by greaser5
So, my heater blower motor in the engine bay is making the dreaded noise and it's time to add a bypass. In doing so, I still want heat..
It is possible to buy just the fan somewhat inexpensively (less than a bypass) and then you don't have to worry about anything.
Old 01-07-2016, 01:32 PM
  #8  
justin-in-athens
Pro
 
justin-in-athens's Avatar
 
Join Date: Aug 2009
Location: Athens GA
Posts: 619
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by JasonAndreas
It is possible to buy just the fan somewhat inexpensively (less than a bypass) and then you don't have to worry about anything.
I want to say they run about $150 on ebay. Mine has been running fine for a couple of years now.
Old 01-07-2016, 02:21 PM
  #9  
DobermanDad
Drifting
 
DobermanDad's Avatar
 
Join Date: Dec 2014
Location: Michigan
Posts: 2,128
Received 6 Likes on 6 Posts
Default

I have a spare fan blower if you want to buy it.

The reason I did my mod, is because I'm using an RS heater bypass duct.
Old 01-07-2016, 02:48 PM
  #10  
Spyerx
Rennlist Member
 
Spyerx's Avatar
 
Join Date: Mar 2012
Location: SoCal
Posts: 16,485
Received 1,730 Likes on 1,058 Posts
Default

timely thread. I have a 91. I am putting in the heater blower bypass, removing my fan (not selling it!).

Is #1 the best option for my situation, which will allow me to keep heat functional?
Old 01-07-2016, 02:55 PM
  #11  
LPMM
Drifting
 
LPMM's Avatar
 
Join Date: Nov 2004
Location: Texas+France
Posts: 2,194
Received 130 Likes on 80 Posts
Default

Originally Posted by greaser5
So, my heater blower motor in the engine bay is making the dreaded noise and it's time to add a bypass. In doing so, I still want heat... So I need to make some wiring changes. While searching I found two ways:

1. A homegrown method described as "definitive" as found here:
https://rennlist.com/forums/964-foru...-solution.html

OR:

2. Add a bridge relay (964.610.184.00) and then pull the fuse as described here:
https://rennlist.com/forums/993-foru...l#post10404484

Option 2 seems cleaner to me and I'd like use it... But will this retain my heater? Anyone done this?
I bought the RS heater bypass duct and ordered the relay as shown in Option 2, but I won't able to test anything until Springtime since I took the car off the road for the winter season.
Old 01-07-2016, 03:17 PM
  #12  
Mezger
Instructor
 
Mezger's Avatar
 
Join Date: Feb 2014
Location: Isle of Palms, SC - Munich, Germany
Posts: 187
Received 1 Like on 1 Post
Default

Could anybody tell me where to get a non Carbon bypass?
Old 01-07-2016, 03:34 PM
  #13  
DobermanDad
Drifting
 
DobermanDad's Avatar
 
Join Date: Dec 2014
Location: Michigan
Posts: 2,128
Received 6 Likes on 6 Posts
Default

Originally Posted by Mezger
Could anybody tell me where to get a non Carbon bypass?
Looks like Patrick Motorsports has it:

http://www.patrickmotorsports.com/pa...ht-heat-elbow/
Old 01-07-2016, 03:36 PM
  #14  
DobermanDad
Drifting
 
DobermanDad's Avatar
 
Join Date: Dec 2014
Location: Michigan
Posts: 2,128
Received 6 Likes on 6 Posts
Default

Originally Posted by Spyerx
timely thread. I have a 91. I am putting in the heater blower bypass, removing my fan (not selling it!).

Is #1 the best option for my situation, which will allow me to keep heat functional?
I think you should only have to do the bridge like on #2 since you have a later car.

Actually here man:
https://rennlist.com/forums/964-foru...er-bypass.html

That guy has a 91 like yours.





Surprised no one else has posted on this. It's been awhile since I did mine.
Old 01-07-2016, 03:43 PM
  #15  
greaser5
Rennlist Member
Thread Starter
 
greaser5's Avatar
 
Join Date: Mar 2013
Posts: 144
Received 3 Likes on 3 Posts
Default

Originally Posted by Mezger
Could anybody tell me where to get a non Carbon bypass?
This is the porsche part number for one:

993-211-941-00


Quick Reply: Heater bypass wiring - which way is best?



All times are GMT -3. The time now is 10:14 PM.