Auto HVAC - Wiring Eletric Diagram

[BlackBullet]

Hi guys,

Please, someone has the eletric diagram of the Auto-HVAC?

On mine, there is one channel that is not operating, the central flap! It may has some bad eletric component on it!

I do not need the wiring diagram from the HVAC until the flaps... I need the diagram from the inner of HVAC!

Thanks a lot,


Best wishes,

[S2central.net]

Start your search from here - follow links to your car, but they all point to same thing from memory with climate system from 10/92 onwards.

http://www.s2central.net/S2_Schematics/

[BlackBullet]

Thank you Paul,

I didn´t found the eletric schematic from the E87 unit!

Do you have?

[S2central.net]

You want the schematic INSIDE the E87 ?

Or can you not find the climate control schematic ?

Anyway - with VAGCOM you can find faults...

[BlackBullet]

I need the INSIDE schematic of the E87!

Do you have?

[S2central.net]

NO - why so sure the fault is inside E87 ?

[BlackBullet]

Because, when i select the frontal flap, there is no energie at the wire to the G112, and I am sure that there is no problem with the wire!

If I select other flap, i is possible to messure the voltage at others channels!

[S2central.net]

mmmm - well that does smell of a fault inside E87 alright... Maybe just a bad joint or a failed output driver. They are easily found on eBay - probably less hassle than tearing one apart - look for ones from LHD B3 or B4 models. The ones from B5 models have identical hardware, but run different software which make it more complicated as you need to code your system to 5cyl LHD... This is to make head unit ignore fact there is no compressor speed signal - this is a unique attribute of S2/RS2 aircon for reasons unknown to me.

I have never opened an E87 but I'd be confident there is some sort of ROM/EPROM chip that contains the software for it - you could easily swap this from your faulty E87 into a good one from B5 model and it would behave like a B3/B4 model.

I have an RS2 head unit here that I could open up for investigative surgery if that would help. Bit of fun for a friday night over a couple of beers

[S2central.net]

Opened an E87 today for 1st time... An RS2/B4 coded one - bad news is that the micro/eprom is hidden underneath a metal screen on the board that is heavily soldered down... Well I assume it must be under there as it sure aint anything else that is visible on the board. I'd need a hotter iron to remove it and I am reluctant to do that with this rare item. If someone has a scrap/damaged head unit I would be much happier to investigate that one - there is every possibility that the chip in question is not even socketed and it must be surface mounted so I don't hold out much hope yet.

[BlackBullet]

Thank you Paul,

I am still investigating mine E87! At first, I am trying to locate the bad component! If I have some news, i will post here!!!

I know that is a little bit difficult to find the eletric schematic from the inside of E87, but I am still looking for!

Best wishes,

[S2central.net]

I think you have no chance to find the internal schematic. Good luck though.

Would be better to visually trace the circuitry from the pin(s) you suspect are faulty - then compare with good pins (s). My bet is a failed output driver - but no clue what chip that is.