Intermittent No-Start / Clicking - Worn Starter Contacts, Bad NSS, and Corroded Battery Cables

Electricalintermediate✓ OP Confirmed

Problem

1987 Supra NA automatic would intermittently fail to start. Only a clicking sound from the passenger side starter relay was heard with no cranking. The problem was progressive - initially lasting 10 minutes before the car would start, then growing to 30+ minutes, and eventually the car would not start at all until the next day. Jumping the car did not help.

Clicking from passenger side kick panel (starter relay) but no crankingIntermittent no-start that worsened over timeCar would sometimes start fine even after a 30 minute driveBanging on starter did not helpEventually car would die completely when attempting to startWeak cranking when it did start

Root Cause

Three overlapping issues: (1) Worn starter solenoid copper contacts - the flat contact surfaces had lost material where the plunger touches, requiring extra plunger travel and causing intermittent connection. (2) Dirty/dried-out neutral safety switch (NSS) contacts - the 35+ year old factory grease had dried and crusted on the copper contacts inside the transmission-mounted NSS, preventing reliable electrical connection in Park position. (3) Corroded and poorly connected battery cable terminals - both positive and negative battery connections had corrosion, loose fit, and damaged wiring including a disconnected fusible link wire.

Confidence

Moderate confidence — Original poster confirmed this resolved the issue

View Original Thread →Posted October 2023 on SupraForums.com