Simple Issues (check these first):
* Dead Battery: This is the most common reason. Check the battery voltage with a voltmeter. It should be around 12.6 volts when fully charged. If it's low, you may need a jump start or a new battery.
* Loose or Corroded Battery Terminals: Clean the terminals with a wire brush and baking soda and water solution, ensuring a good connection.
* Faulty Starter: The starter motor might be failing. A clicking sound when you turn the key is a common symptom.
* Dead or Failing Alternator: While this won't prevent the car from starting initially, a failing alternator won't recharge the battery, leading to future starting problems.
* Insufficient Fuel: Check the fuel gauge. Seems obvious, but it's an easy overlook.
* Bad Ignition Switch: This controls the power flow to the starter and other systems. If it's faulty, it may not send the necessary power to crank the engine.
* Security System Issues: Some Transports had anti-theft systems. If the system is malfunctioning, it might prevent starting.
More Complex Issues:
* Fuel Pump Problems: The fuel pump might be failing or not receiving power.
* Fuel Filter Clog: A clogged fuel filter restricts fuel flow to the engine.
* Distributor Issues (if applicable): Older vehicles use distributors; if the cap, rotor, or ignition coil is faulty, the engine won't start. (Less likely on a '95, but possible depending on engine type).
* Crank Sensor Issues: The crankshaft position sensor tells the computer the engine's rotational position. A bad sensor will prevent starting.
* Computer Problems (PCM): The powertrain control module (PCM) controls many aspects of the engine. A faulty PCM can cause numerous starting issues.
* Wiring Problems: Damaged or corroded wiring anywhere in the starting circuit can prevent the engine from cranking.
* Security System Issues (more detailed): A malfunctioning immobilizer system can also prevent starting.
Troubleshooting Steps:
1. Start with the simple things: Check the battery, terminals, fuel level.
2. Listen carefully: Any unusual noises (clicking, grinding) when turning the key give clues to the problem.
3. Visual inspection: Look for any obvious signs of damage to wiring or components.
4. Use a multimeter: Check battery voltage, and potentially other electrical components if you have experience.
5. Consult a repair manual: A repair manual specific to your 1995 Pontiac Transport will provide detailed diagrams and troubleshooting information.
If you're not comfortable working on cars yourself, it's best to take it to a qualified mechanic for diagnosis and repair. They have the tools and expertise to pinpoint the problem efficiently.
