Top-Quality Glow Plug Relays

Struggling with cold starts? A faulty Glow Plug Relay is a common, easy-to-fix culprit. Think of it as your engine's heavy-duty starter switch. It uses a small signal from your key to connect massive power from the battery directly to your glow plugs, making cold starts possible.

Signs of failure are simple: difficult cold starting, no audible 'CLICK' from the engine bay when you turn the key, or a flashing glow plug indicator on your dashboard.

Understanding the 4 Terminals on Your Relay

Most relays have four connection points that work in two pairs:

  • Two Large Terminals (High Power): One post receives constant power from the battery. The other sends that power out to the glow plugs.
  • Two Small Terminals (Control): One post receives the 'turn on' signal from the ignition. The other is a ground to complete the circuit.

When the two small terminals are activated by your key, they create a magnetic switch that connects the two large terminals, sending power to the plugs.

Pro Tip: When diagnosing, use an amp clamp to confirm current is flowing to the glow plugs. Voltage alone can be misleading. Always check your service manual for your specific wiring diagram.

FridayParts Glow Plug Relay Catalog

Find the guaranteed-fit, reliable replacement for your machine below and get back to dependable starts.

  • For BMW: 3, 5, 6, 7 Series (E46, E90, etc.), X Series (X3, X5, X6)
  • For CASE: Excavators (CX27B, CX31B, CX36B, CX50B, etc.), Compact Tractors (D35, D40, D45)
  • For Cub Cadet: Tractors 7000, 7200, 7205, 7260, 7265, 7300, 7305, etc.
  • For Deutz: Engines BF4L2011, BF6L914C, BF4M1012, BF4M1013, TCD2012, TCD2013, etc.
  • For Hitachi: Excavators EX27U, EX30U, EX35U, EX40U, EX50U, EX400, EX450, ZX14-3, ZX16-3, ZX22U-2, ZX30U-3, ZAXIS Series, etc.
  • For Iseki: Tractors TU120, TU130, TU140, TU150, TU160, TU170, etc.
  • For Isuzu: Engines C240, 3AA1, 3LB1, 4JA1, 4JB1, 4JG2, 4LC1, 4LE1, 4LE2, 4JJ1, 6HK1, etc.
  • For John Deere: Engines (3009, 3011, 3012, etc.), Excavators (17D, 17G, 26G, 27D, 35C, 35D, 35ZTS, 50C, 50D, etc.)
  • For Kioti: Tractors DK45, DK65, DK65C, LB1914
  • For Kobelco: Excavators 27SR-5, 30SR, 35SR, 50SR, SK02, SK03, SK035, SK45SR, SK55SRX, etc.
  • For Volvo: Excavators EC13, EC15, EC20, EC25, EC30, EC35, EC45, EC50, EC70, EW50, EW70, etc.
  • For Yanmar: Engines 3TNV76, 3TNV88, and models compatible with NGK G71Su relays.
  • Etc...

Find the Right Glow Plug Relay for Your Machine at a competitive price right now! If you have any questions, feel free to contact our expert teams. They will reply to you readily and professionally within 24 business hours.

Frequently Asked Questions

Is a glow plug relay hard to replace?

No, it's usually a simple plug-and-play job! It's often found in the engine bay's fuse box or on the firewall. Just be sure to disconnect the battery first.

My glow plugs are new, but the engine still won't start. Could it be the relay?

Yes. New glow plugs can't work if they don't get power. If the plugs are good, the relay is the next part to check.

What happens if I ignore a bad relay?

You'll continue to face frustrating start-up issues. A relay stuck 'on' can also burn out your new glow plugs.