After run relay location or diagram

[CaffeinatedSoul]

I'm trying to track down why my car has no heat at idle but works fine under high rpms. I've tried the usual things everyone mentions and still no luck.

Here is a list of what I tried.
New water pump
new auxiliary pump
thermostat
coolant temp sensor replaced to "the green one"
Flushed heater core with CLR
Tried to bleed the heater core before aux pump but no fluids in core to bleed.
bleed heater core a day ago with coolant coming out of tube.
Both tubes are hot.

I've tried to find a diagram of the relays for the after run only to find pages of diagrams for B6's, TT's, and Jetta's. I've read that there is an after run relay for it some place under the driver side dash but have also read it's on the passenger side. One site also mentions something about a after run temp relay or sensor, not sure if that is true for our car.

TLDR: Need diagram that shows after run relay location and relay number.

[Corradovolksb]

The after run relay is located on the passenger side of the dash behind the right side of the glove box. It's a rectangle box with a bracket that is bolted to the dash support. The temp switch for it is on the cross pipe at the back of the bank 2 cyl head. Sorry no diagram.

Your heater core is clogged causing your lack of heat if both hoses at the core are hot the coolant is just flowing through the top of the core. The other cause could be your blend door motor not switching to heat and staying on cold. If you have VCDS you can run basic settings 1 in 08 climatronic module to make sure it's working correctly.


2000 Nogaro S4 stage 2 K&N intake SSAC turbo back exhaust EVOMS DV's SB stage3 daily clutch 42lb injectors V8 FSI fuel pump. 91 and E85 personally tuned.

[CaffeinatedSoul]

Full scan with vcds shows everything is fine. Is it possible that the after run pump is just not running or moving enough coolant to the heater core to produce heat? When I flushed it with CLR I had a bit of junk come out but otherwise seemed fine. I assume it's a flow issue only because at one point while trying to bleed the system (before the new pump) I accidentally pulled the hose completely off. I expected coolant to come flying out since the car was running but not hot yet. There was absolutely no coolant going in or out of the core.

[zillarob]

After run pump only runs when the car is off so wouldnt have anything to do with it.

Clogged heater core will do exactly what you describe.
Air pocket can also, but they usually sort themselves out pretty quickly.

[Corradovolksb]

Ya the pump runs after you shut it off but only if the temperature reaches 219 with the stock after run switch. That's why people replace the after run switch with a Lower temp one. If your system is blead correctly and still no heat it's gota be the core.


2000 Nogaro S4 stage 2 K&N intake SSAC turbo back exhaust EVOMS DV's SB stage3 daily clutch 42lb injectors V8 FSI fuel pump. 91 and E85 personally tuned.

[CaffeinatedSoul]

So Im not saying anyone hear is wrong, Im just stating my findings on this.

I flushed heater core bleed the system several times - No heat at idle
Replaced after run - No heat at idle
Bleed heater core 2 or 3 times after run - Heat is coming on ALOT better now. I can actually hold most heat at idle, I assume there is more air.

I believe the after run can fail in such a way that it can limit the amount of coolant to the heater core. So I guess its something to think about if you have the same issue and know your after run is bad.

[Zba]

So Im not saying anyone hear is wrong, Im just stating my findings on this.

I flushed heater core bleed the system several times - No heat at idle
Replaced after run - No heat at idle
Bleed heater core 2 or 3 times after run - Heat is coming on ALOT better now. I can actually hold most heat at idle, I assume there is more air.

I believe the after run can fail in such a way that it can limit the amount of coolant to the heater core. So I guess its something to think about if you have the same issue and know your after run is bad.

No.

You need a heater core.