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2008 2.5 AC Schematics (Wiring Diagram)?

185 Views 15 Replies 2 Participants Last post by  billymade
Could someone provide an image or PDF of the wiring for the AC circuit for a 2008 Beetle 2.5. The 2008 Beetle does not have the coolant temp switch mounted in the radiator. It's temp switch is mounted in a flange between the head and air box. Everything I'm finding is for the early New Beetles. Thank you!
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You might view online or download the eRWin factory VW manual here:

For simplified redrawn wire diagrams check Haynes, Mitchell1 or AllData.

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No joy at workshop-manuals and only manuals. Mitchell1 and AllData want around $200 a month for access. Thank you for the information.
The Mitchell1 and AllData have "diy" type subscription services; (which is MUCH cheaper), then the "pro" access which IS $200 a month. Haynes, has a paper manual and online access as well.

eRWin, VW's subscription service; is another option with the VW factory service manuals, downloadable in .pdf file format, you can save to your hard drive.

The simplified and redrawn wiring diagrams; are probably, easier to understand from AllData, MItchell1 or Haynes.
I prefer Bentley manuals. I pulled the trigger on Mitchel1 for $20 a month. It appears to be correct. I'l check out erWin for future reference. Thank you!
If you can share this wiring diagram information and discuss with us the issues you are working on, this could help others with similar problems in the future (searching this site). The more everyone shares, discusses their diagnostics and repairs, the more everyone benefits! Thanks.

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2008 New Beetle AC and coolant fan wiring diagrams, schematics. The issue I'm dealing with is the AC will not turn on. '08 Beetle 2.5 BPS automatic, hatchback. The AC switch lights up as designed but the coolant fan and compressor will not turn on. We've replaced the four pin coolant sensor, verified voltage at the high pressure switch (it fluctuates 2 to 12 volts) and fuses related to the AC system. If the four pin sensor is disconnected the coolant fan will run and the red flashing coolant light will illuminate. The two pin connector at the compressor is grounded and has apx 3 volts on the second pin when the system is off. We have not checked for voltage at the compressor with the two pin connector connected with a pin through the wire. We have yet to put gauges on the system. Any suggestions? Thank you.

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I would verify compressor status with a vw scan tool; like vcds and hook up some a/c gauges and see what the high and low pressures are.

This discussion maybe helpful:

(Note tech info on harness to compressor from ross tech and VW Tech Bulletin):

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VCDS and gauges is the next step. Thank you.
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Put gauges on. Low side 47lbs, high side 50lbs engine off. Engine running no change, compressor does not turn on. VCDS said compressor was on. Bad compressor/solenoid is my guess.
Here is a good page to review for evaluating things for a/c diagnosis:

AC pressure gauge readings — Ricks Free Auto Repair Advice Ricks Free Auto Repair Advice | Automotive Repair Tips and How-To

Internet q/a's on a/c pressures:

An A/C System that is working properly should have 150 PSI on the high side and 30 PSI on the low side.

What are my A/C pressure readings telling me about my A/C system?

50 PSI / 50 PSI = The clutch is not engaging.

Can you take a look at the sticker on the compressor; for the VW and possibly Sanden part #'s, so we know, what compressor you have? Some of the later compressors didn't have a clutch but some do; from 2006-on the New Beetle was a mix of Mark IV and Mark V parts, so that makes things more confusing.

The clutchless type, run all the time; while, a clutch type, is obvious, when it engages and puts a load on the engine.
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Im not sure the make of the compressor but it is not a traditional one wire compressor.
Please, inspect the compressor, identifying which one it is (brand, part #, etc); can help us, help you and hopefully enable the next step, trying to jump the compressor and see, if the compressor engages (thus, the question if it is clutch or clutchless type).

Here is a run down; of diagnostic steps, the basics should apply but the compressor type, maybe different (clutch/non clutch)? Because, you have the later 2.5L; the a/c system may have a different later compressore type?

Tech Tip: Volkswagen Has No Power to the A/C Compressor Clutch – UnderhoodService
I will have compressor information early next week. I checked the above link. If this Beetle has a 14 pin connector I can not locate. Question. Does the fan turn only if the compressor is on? The compressor (Motronic ECU) tells the fan to run? Thank you.
These are good questions , (I don’t know); i’ve worked on my earlier 02 Turbo S, which seems to be setup differently? You have service manual info access through Mitchell1 now; time to do some research and maybe print out the pages for the hvac system and familiarize yourself, on how the system is setup, works, compressor is activated, etc?

Please, share about what you research, figure out; we are always learning new things on this site, from each member as they do repairs and this benefits everyone, thanks.

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