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

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.

I have a 90... and now, I'm even more confused as to what to do! :)

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.

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.

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.

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 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.

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/

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. ;)


https://cimg9.ibsrv.net/gimg/rennlis...131a2d95a4.jpg


Surprised no one else has posted on this. It's been awhile since I did mine.

This is the porsche part number for one:

993-211-941-00