Why your car won’t start

The process that goes on from the moment you put the key into the ignition to the point where the engine is running involves a few steps. Once you know at which step things go wrong, you will have a better idea why your car will not start and what to do. File Photo

What you need to know:

If you replace your car battery and the vehicle still won’t start, there are a number of things that might have gone wrong with it. David S. Mukooza explores some.

When a car refuses to start, the first thing one thinks about is the battery. But when Peter Mugwanya’s car refused to start, a quick check by the mechanic revealed that the battery was okay and he did not have any idea why the car had refused to start. The mechanic suggested taking the car to a garage to check other things that could be wrong.
According to Ronald Lubega of Grace Lubega Motors in Rubaga, a dead battery is the number one cause of a no-start and usually jump-starting the car will be the easiest way to get back on the road. But it might also be a problem of the clamps. He adds that drivers should make sure the clamps ccannot easily slip off the battery terminals and tightening loose clamps may get you on your way.

Jump starting the car
Ronald adds that if the clamps are secure, the battery then likely needs a jump. The trouble now emerges on the right way to jump-start a car. He says drivers should know the proper way to jump-start a vehicle. Making the wrong connections can cause sparks. Improper polarity may also damage either the donor or recipient vehicle.
“Learn the proper sequence of connecting and disconnecting the cables as well as where the clamps should be attached”, says Ronald.
Choose heavy gauge cables because the lower the gauge number, the heavier the cable. Cheap cables may not be able to carry the electrical current to start the stranded car. The insulation on them may even melt.
If you have doubts about the battery’s condition, have it tested. With today’s hand-held testers, the job only takes a couple of minutes. Many auto parts stores and some repair shops offer free testing where they will not only check the battery condition, but also the charging and starting systems. If the battery is sorted and still your car refuses to start, other factors might be to blame.

Faulty alternator
According to Bosco Kigongo, a mechanic with Icony Garage in Kinawataka, an alternator is an electrical generator that converts mechanical energy to electrical energy in the form of alternating current. If the alternator is not fine, the battery may not get charged.
“Although the alternator could be the culprit here, do not overlook a worn or slipping accessory drive belt,” says Kigongo. If the alternator fails or the belt breaks, a warning light will show and if the charging system output is poor, there may be no warning light.
Kigongo says even a perfectly functioning alternator may not recharge the battery during short trips, especially if the headlights, wipers, heater, radio, rear window defroster and heated seats are turned on. Therefore, this may cause a no start.
A bad starter (commonly known as selefu). Kigongo says a bad starter may give the illusion of a weak battery if it draws more current than the battery is able to supply, it will spin slowly and draw excessive power. It will make that funny sound, similar to a weak battery.
If you hear a nasty grinding clashing sound, the starter drive gear or the engine’s flywheel (ring gear) may have damaged teeth. If the starter does not even turn, its relay may be shot or the ignition switch could be the culprit hence causing a no start.

Steering wheel lock
There is no driver who has not experienced this because occasionally, the key will not turn in the ignition switch. According to Kigongo, as an anti-theft feature, the steering wheel locks when the key is removed. Sometimes, the wheel moves back against the parking pawl (a device fitted to the automatic transmission of motor vehicles to lock it up when the vehicle is parked and to prevent it from moving).
Therefore this then prevents you from turning the key. “Try to gently move the steering wheel left or right as you turn the key and you will be good to go, “he advises.
If the starter cranks the engine normally, but the engine refuses to run, the battery, starter and alternator are probably fine. Therefore the cause lies elsewhere. Ronald says then it will need a bigger investigation into what could be the problem but it’s another cause of a no-start.

A weak fuel pump
Kigongo says even if there is plenty of fuel in the tank, a weak fuel pump or failed fuel pump relay may prevent the fuel from reaching the engine. He adds that if you listen closely, you should be able to hear the in-tank pump running for a few seconds when you first turn the key to the “on” position before cranking the starter.
However if it does not and the fuel cannot be pumped to the engine then the car will not start.
Another cause of a no start could be your spark plugs. Ronald Lubega refers to these as secondary ignition system problems, although rare nowadays, can cause a no-start. It is easy to forget about the replacement of the spark plugs and them not having the ability to deliver an electric current from an ignition to the combustion chamber, Ronald says will most obviously lead to a no start.

Security system
Bosco Kigongo, a mechanic with Icony Garage in Kinawataka, says because of the so many incidents of car theft in Uganda many people have adopted security systems for cars but the electronics of the security system can be devil drivers. Trying to start the car with the wrong ignition key can lead up to a 20-minute delay.
Similarly, remote keyless entry and remote starting devices have been known to create havoc. If you lock your car using an alarm remote and on return you use the key to open automatically the car will refuse to start and this will be a simple issue that one might not know hence causing delay or even calling a mechanic. This brings us to a conclusion that it is not only the faulty battery that will cause a no- start but rather several issues.