Fan, A/C and water-pump relays and fuses (EWD)

Tags: #relay · #fuse · #cooling-fan · #wiring-diagram · #water-pump

Source: the factory electrical wiring diagram (EWD) pages shared as PDFs in the group. Values below are as printed on the diagrams; one rating is inconsistent on the page itself (see PWM fan).¹

Cooling fans. The R12 Medium Speed Fan Relay switches the Main and Additional Fan Motors through fuse Si9 "Medium Speed Fan" 40A, controlled from ECU (2.0L) pin 50. The R16 High Speed Fan Relay uses Si11 "High Speed Fan" 30A, controlled from ECU (2.0L) pin 68. The R21 PWM Fan Relay (2.0L) is shown with Si11 "PWM Fan" at 50A, which conflicts with the 30A printed on the high-speed fan fuse label; confirm against the PDF before relying on either value.¹ For fan-motor failure stories see Cooling fan motor failure and parking sensor glitches.

A/C compressor relay. R1 A/C Compressor Relay uses Si25 "Compressor" 10A to drive the compressor magnetic clutch; its ECU pin is 69 on the 2.0L, 42 on the 1.8T and C_L4 on the 1.8TD.¹

Electric water pump relay. R20 Electric Water Pump Relay uses Si21 5A for the electric water pump (1.8T, 1.8TD and 2.0L variants), with ECU pin 39 on the 1.8T and B_N3 on the 1.8TD.¹

A/C circuit page. The A/C wiring page shows fuses Si25 "Compressor" 10A, Si5 "Blower" 40A, Si67 "Seat Heater" 5A, Si7 "Defroster" 40A and Si1 "BNT" 40A, with main fuses Si13 125A, Si71 (generator) 175A and Si72 (main) 175A. The compressor magnetic-clutch connector is E12 (2.0L), E11 (1.8T) or E75 (1.8TD); the triple pressure switch is F39. The blower is I18; the page also covers the temperature damper motors (driver-side and front-passenger-side temperature, ventilation, mode, inner/outer circulation), the automatic A/C control unit (ATC) and the rear-window defroster relay.² See Air conditioning — refrigerant system and diagnosis for the refrigerant side.

Media

📎 Attachment: 35818_Z015.pdf — EWD page 1115: fan relays R12/R16/R21, A/C compressor relay R1 and electric water pump relay R20 with fuses and ECU pins

📎 Attachment: 35827_Z024.pdf — EWD page 1124: A/C compressor clutch and pressure switch connectors, blower, damper motors, ATC unit, fuse ratings

Related pages

• Water pump — brands and fitment
• Water pump — price and failure modes
• Thermostat failure — symptoms and diagnosis
• Wiring diagram (EWD) fuses and relays
• Radio/A-C/display/fan failure — blown fuse

Sources

This page is compiled from 2 community messages. Every fact carries a numbered reference to its original author and message.

Last updated: 2026-10-29