Troubleshooting guides
Step-by-step help for finding faults, linked to the factory wiring diagrams.
E30 No-Crank / No-Start Guide
Click through what the car is doing and get to the most likely cause, with the wiring pages for each circuit.
Fuse and relay finder
Type a fuse number or a circuit, such as sunroof or fuel pump, to see what it feeds, what else shares it, and where it is drawn.
Relay numbers, and how to jump a relay socket
What 30, 85, 86, 87 and 87a mean, the E30's key relays, and how to prove a fuel pump works by jumping its relay socket.
Fitting a new radio or head unit
Which wire is which at the factory radio, how to wire a new head unit, the antenna and speakers, and the sound-system amplifier.
Battery Drain Finder
Find what is flattening the battery when the car sits: measure the draw, pull fuses, and track it to a circuit.
Ground points guide
Where the grounds are, what each one feeds, and how to test and clean them. Bad grounds cause many odd faults.
Central Locking Troubleshooting
Find out why the central locking has stopped working, from the fuse and control unit to a single door motor.
Power Windows and Sunroof Troubleshooting
Why the windows or sunroof stopped working: the shared fuse, the circuit breaker, switches, motors and wiring.
Gauges and Dash Lights Troubleshooting
A dead cluster, a fuel gauge that jumps, a dead tach, a wrong temperature reading, or dash lights that are out.
Repairing old harness and connectors
Finding damage, re-wrapping crumbling loom, repairing broken wires and connectors, and when to replace a harness.
Add remote locks to an E30 for about $15
Fit a keyless remote to the factory central locking in about fifteen minutes, with a cheap universal kit wired in the boot.