Tech Tips

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Volkswagen

VW models with Air Condition - No Start Condition

Before changing multiple Alternators or Starters in VWs equipped with A/C due to a "won't start" or "no crank" condition, check out the radiator cooling fan.  What kind of logic is this?

All Volkswagen vehicles equipped with airconditioning (except Vanagon) are subject to a condition during high ambient temperatures (105F/41C) where the battery is continually drained due to the radiator fan kicking on at high speed with the ignition shut off.  It seems that under these high heat conditions, the gas pressure of the R12 refrigerant can activate the A/C high pressure switch and in turn, trigger the high speed radiator fan relay to activate the cooling fan.  Volkswagen has instituted a replacement fan relay switch (p/n 321 919 505A) which, along with some minor modification of the A/C high pressure switch wiring, will eliminate this problem.  Replacement relays and wiring instructions are available through your local VW dealer parts department.

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