Volvo 940 Horn Relay Location: Step-by-Step Guide

Finding the Horn Relay on a Volvo 940 (1991–1998)

The horn relay on the Volvo 940 is located in the engine compartment relay box near the battery. Here's how to find and access it:

Tools Needed

• Flathead screwdriver (for relay box cover)
• Flashlight
• Optional: Multimeter or test light for testing

Step-by-Step Location Guide

1. Open the Hood: Release the hood latch and prop it open securely.
2. Locate the Battery: On the driver's side (left side facing the engine), near the front fender.
3. Find the Relay Box: Look to the left (outboard) of the battery. You'll see a black plastic box with a blue electrical connector plugged into its side.
4. Remove the Cover: Unclip the plastic cover of the relay box (usually 2–4 clips).
5. Identify the Horn Relay: Inside, you'll see several relays (typically 4–6). The horn relay is usually a standard ISO micro relay (4 or 5 pin). It may be labeled on the underside of the cover or on a diagram in the owner's manual.
   • Common position: Often the outermost relay or the one closest to the blue connector.
   • If unlabeled, consult the wiring diagram for your specific model year (940, 940 Turbo, 960, S90/V90 share similar layout).

Testing & Replacement

• Swap Test: Exchange the suspected horn relay with an identical one from the same box (e.g., fog light or AC relay) to confirm.
• Multimeter Test: Check for continuity across the coil terminals (usually 85/86) and switching function across load terminals (30/87).
• Replacement: Pull straight out; push new relay in until seated. Use exact same part number (e.g., Volvo 3549187, 9135752, or generic 4/5-pin 12V 30/40A micro relay).

Other Possible Causes if Relay Is Good

• Horn itself (test by applying 12V directly)
• Horn switch in steering wheel (clockspring/contact ring)
• Wiring harness damage (check near radiator support, hinge area)
• Fuse (check fuse box—often fuse #6 or #10, 15A–20A)

Tip: The relay box cover often has a diagram. Take a photo before removing relays. If your 940 has dual horns, both are triggered by this single relay.