911porschefan

I have a question maybe someone can answer. My heater blower motor makes horrible noises so I have disconnected it so there is no power to it. Should I still get heat/air coming out of the front vents when the dial is turned to high and hot? Should the front vent blowers still work without the heater blower on the motor?

My car is a florida car that I have brought up to Canada, not sure if PO disconnected everything to do with heat since he did not need it.

ThomasC2

Yes you should, but you have to jump wire the fan realy in the rear. Otherwise the CCU thinks there's a problem with the fan and shuts down the system when you turn up the heat. If the error has kicked in (gives you only low speed on front blowers and no heat) you have to use the Bosch Hammer/or Scantool to reset the error codes.

I've attached a pic showing you how to jump wire the relay. This is the same thing you do if you want to use the bypass tube from the cup cars instead of the rear fan.

Thomas

anto1150

if it's stated by a swedish...

jimq

um we do need heat in Florida!

911porschefan

Thomas - thanks for pointing me in the right direction. I will try that.

Jim - you guys have almost had more snow than us here in Canada this year.

xeps

My blower motor similarly died, and I think you will find the airflow without it quite lacking , even when jumpered.

If you choose not to replace the blower, a good option is to get a bypass tube.. carbon fibre ones are available from fabspeed and elsewhere.

As a cheap alternative I would suggest removing the blower motor assembly from the housing. This gives you a setup very similar in function to the bypass tube, though perhaps somewhat less efficient.

911Jetta

Let me confirm this... (sorry to hijack)

when installing a heater bypass tube (functional heat, albeit reduced velocity) , all you need to do unplug the wires, unbolt it, and set up a relay jumper (as in Thomas' picture)?

ThomasC2

Yes, that's correct.

Thomas

dan79brooklyn

On my '93 the heater blower makes a terrible noise so I have the fuse pulled.
I get PLENTY of heat into the cabin even with the heater set at 12 o'clock and no fan on.
I can cook my face if I turn the heat all the way up.
No jumpering required....BUT I don't get any heat on my feet. ?

Gus

One issue that you may run into that the 964 has is if you jump the relay it leaves a circuit open for some reason and drains the battery - What some of us have done is install 2 relays to do what the 2 wires do, but only when activated by an ign switched control wire - if you probe around you can find one in the rear fuze box to run to the relays.

911porschefan

Well I did what Thomas said to do and it worked. I'll see if I get a battery drain issue.

Gus, can you elaborate on this for me, not to good with electronics. What two types of relays should I use and where should I get an ign switched control wire. How do I put two relays into that one spot.

911porschefan

I find this strange as I wasn't getting any heat at all. Could I have a problem with my front blowers? How do I check if these are working. I'm getting air blowing now that I did the jumper but its not as hot as I thought it would be, more like warm air blowing. On the vent closest to the driver door, I only get cold air from there? Is that an indication that something is wrong with my heat?

ThomasC2

the battery draining is a bit strange. I don't have it, from what I know at least. I always use my trickle charger when the car sits in the garage and it's more or less always in "rest-mode".

Thomas

Duck

I have the heater bypass tube and have plenty of heat. If you are getting warm or cold air, you may have an issue with the mixing servos.

sergiDA

I am using the carbon Heater bypass tube, same as in the cup cars , and the fact is that I have no heating at all. Here in Barcelona is not a big issue, but this trick you just showed us will help to get at least some hot air inside which is not a bad thing at all.

Thanks a lot!!