New Holland Timer Relay SBA385870301 TC35 TC45

Test each glow plug individually with a multimeter — a functioning plug will show low resistance (typically under 2 ohms). If the plugs test good but still don't heat up during the pre-heat cycle, the timer relay is the likely culprit since it controls whether power reaches the plugs at all. If the relay clicks but plugs still don't heat, also check the wiring between the relay and plugs. At $15.99, the relay is almost always worth replacing first.

That's the classic symptom of a failing glow plug system. In warm weather, compression alone is enough to ignite the fuel. Below around 40°F, the glow plugs need to pre-heat the combustion chamber for reliable ignition. If the relay isn't activating the plugs properly, cold starts will be difficult or impossible even if the engine is otherwise healthy. Replace the relay first, then test the glow plugs if problems persist.

Yes. SBA385870301 supersedes SBA385870300. Both numbers, along with 83965764 and 385870300, are OEM equivalents for the same 12V glow plug timer relay on New Holland TC-series compact tractors. Any one of those numbers on your existing relay confirms this is the correct replacement.

We offer free returns within 30 days if the part doesn't fit or you're not satisfied. Parts must be unused and in original packaging.

Yes. Call (818) 261-3896 and we'll help you confirm fitment, answer installation questions, or troubleshoot issues.

Orders ship same-day if placed before 3 PM EST. Standard delivery is 3-5 business days.