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https://forums.nicoclub.com/vancouverbc-u10923.html
Sat May 12, 2007 9:42 pm
Index of all Tutorials
CAUTION: I know nothing. Refer to factory service manuals and other experts before doing this. This "tutorial" is just my experience . Research safety issues as I know nothing about safety.
1. Try jump starting car to eliminate weak battery(loose or dirty battery cables/terminals).Check fuses.2. Try hitting the starter and solenoid with mallet. The starter/solenoid might be stuck. If car starts, you need new starter.3.Check the clutch interlock switch on clutch pedal. It is often broken.4. Take a $20 multimeter and measure voltage in the ignition wire at the starter.(key turned to start. clutch depressed). The ignition wire can be disconnected close to starter.(the other wire at solenoid is continuous 12v+). If no voltage, work backwards until you find the point where voltage stops. If you have voltage or dont have a meter, see 5.5. (For Experts)WARNING: PUT THE CAR IN NEUTRAL or car will move by itself for the following procedure. Disconnect the harness plug at the starter. The wire is black with yellow stripe on my 1991. Connect this wire directly to positive post of battery FOR A FEW SECONDS. Without the key in ignition at all, the starter motor will crank the engine. If you want to start engine , key will have to be in the "ON" position. ASSUME THE ENGINE WILL START without key in ignition at all, for safety.
If your engine turns over when you supply 12v+ directly to black/yellow ignition wire, you know the problem is the ignition, interlock relay, wiring or clutch interlock switch. You then bypass these individual components to isolate the problem. Clutch interlock switch is often broken.
==================================================THEORY:==================================================The following diagram shows 12v+ coming in from the ignition switch(via interlock relay and switch) and arriving at solenoid. The solenoid has continuous ground so is energized with arrival of 12v+. The solenoid does two things: 1. It moves an arm which connects starter gears to engine 2. it closes a switch which allows 12v+ to go from battery to starter motor. You obviously want the solenoid to connect starter and engine before the starter motor starts moving. Here is a partial list of things that can go wrong:
1.The starter ground or even the engine ground can be bad. You can ground starter by connecting metal parts of starter to engine block. Some people recommend sanding the interface between starter and engine.Also ensure engine is grounded. ie connected to negative of battery.2. The 12v+ wire from postive terminal of battery to solenoid can be faulty.3.The connection between the starter and solenoid can be faulty.4. The 12v+ line from ignition switch(via interlock relay and switch) can be faulty.5.The arm that connects starter gears to engine can be bent.6.Parts store may have given you wrong starter. 7.The solenoid can seized.8.The electric motor(starter) can seize or have other faults.
This next electrical diagram shows the ignition switch, interlock relay , interlock switch. When you turnn key to start power goes to the starter solenoid.
Notes:1. There is no neutral safety switch. It is called neutral switch and has nothing to do with car starting. The clutch interlock switch is probably what you are thinking of. Car wont start without clutch being depressed and clutch interlock switch being closed.