Why Engine Doesn’t Start

You wanted to start your engine but it doesn’t. Why?

There are several factors to consider. You may have electrical issues, weak battery, motor starter problem, and heater switch problem.

Let’s see what your engine’s problem is.

1. When you turn on the key and your dashboard lights are normally functioning I guess you have no electrical lines busted.

If your car’s dashboard is working properly this can help you determine some issues on your engine. However, if the dashboard has electrical line problems it will not help you diagnose any issue on other parts of your vehicle.

2. Now you turn more the key for your heater (for diesel and for older cars) and it works properly. You should be happy that no lines have an issue.

For almost three days I have been puzzled why I cannot start the engine. Most of the time it just clicked and sometimes by accident it cranks.

I brought the battery to the shop to be checked and it’s working well. It’s even fully charged. The next step is to take down the starter for a checkup and possibly repair it. But, it neither had an issue.

By accident, we discovered that the culprit is the heater switch. Never it gave me a problem but only this time.

Let me explain what’s the issue of this heater switch. In an older car, we have this in preparation for the engine start. You have to press this to heat the glow plugs before you fully turn the ignition key. This is only for the first time when the engine is not used for overnight or for around 10 hours during the day.

The experience was that it works when heating the glow plugs but when you totally turn the key to crank the engine it doesn’t work. So it was an accident that this switch is being halfway pressed while the ignition key is turned. It’s weird because the normal way is to heat it, then release the switch and turn the ignition key. So this has to be fixed to bring it back to the usual and normal way.

Why Engine Doesn't Start-Heated Switch


3. When fully turning your key and the engine cranks but it’s slowly turning you may have a weak battery.

There are different reasons why a battery is weak. It may have drained

-draining of battery when parked for a long time may be caused by faulty wiring.
-draining when you are driving is a symptom that your alternator is not working properly.
-or, battery drains because it’s too old and it needs replacement.

4. You turn it more to crank your engine and it clicks but it doesn’t crank. You may be having an issue with your heater switch or starter.

Now if you have no issue with your heater switch and battery and the engine doesn’t crank you may be having an issue with the motor starter. 

A motor starter that has a problem will not crank the engine. You will hear a click but doesn’t turn. It needs to be fixed. If it cannot be fixed, you may need to replace it.


This starter above is still working now. The armature gear has been deformed and I brought it to the lathe machine shop and they rebuilt it. Please read the related article on Armature Gear Rebuild.

And if you are looking for a replacement for your motor starter? You can find it here.





8 thoughts on “Why Engine Doesn’t Start”

  1. Oh, thank you for bringing up this questions and giving answers to them. You see I am currently going through one of this sought of problems and I was thinking I would have to pay to much for the damage. From your explanation, I think it has to do with my battery because I am guilty of turning. My lights one when I have something urgent to do. I should look into that soon. Thank you for your help.

    • Haha! I’m glad this post is timely. Maybe you have overused your battery for other purposes so it drained but that’s not an issue you have to look into, you just stop using it when you know it’s current is enough to start your engine.

      You may have an issue if you did not use it and is draining. Good luck on your driving, Henderson.

  2. I have owned Toyotas for years, and have loved them for their reliability and gas-saving engines that they have (at least the ones that I have owned). They offer enough comfort, are fun to drive, and seldom break down from my experiences. They also last a long time, they are built with quality in mind.

    Having said all that, it was with interest that I came across this article, as no matter how good a car is when the engine does not start, the car is of no use, no matter the model or age. These tips you have highlighted are helpful as a list of checks when this happens. I have had this happen in the past, and it is not a nice feeling, the advice will give me a way to do some quick checks and fix (hopefully). Thanks!

    • Good to know you are one of the owners of Toyota, Dave. I can affirm that because of the specimen I’m using for my blog is Toyota L-the first engine of the L series. This engine was invented in 1977 and is now still working, and is efficient. The only drawback is the smoke which is unfriendly to our ecological system. I know you understand how this diesel engine is built. However, it’s not so obsolete compared to newer brands this time when it comes to the issue of smoke-belching.

      I am happy that this post can help you in a little way. Good luck with your Toyota driving.

  3. My car used to die every time I stopped at a light or stop sign. It was a 1996 saturn. I would have to jump out of the car with a portable battery and jump start the car. Then hop back in the car start it then detach the portable battery and go. It was really funny but pretty dangerous. I finally realized that the alternator was bad but the car died on me before I got it fixed. Anyway, thought I would share my funny story with you. I no that your advise would have helped save my car before it died.

    • Desiray, I commend you being ready all the time because you carry with a portable battery. Your experience has happened to me maybe twice.

      Anyways, engine stalling has different causes:

      Why it suddenly stalls? Try to check the electrical circuit relays- https://mydreamwheels.com/circuit-relay-related-issues

      If the engine stalls and it doesn’t crank and you need another battery to start the engine-this means your battery is drained and is weak to crank the engine.

      Causes: 1) the battery may not be charging-maybe it has a defect.
                     2) if the battery has no defect maybe your alternator is not doing its job.
                     3) if the alternator is functioning normally but the electrical supply to charge the battery is weak you may
                         have problems with the voltage regulator. 

      All these should be checked one after the other.

      Thank you for leaving your comment. Good luck with your driving.

  4. Hi Jimmy,

    Some great and easy to follow steps on diagnosing what the issue could be with your Toyota engine. I have a Rav 4, which up until now (fingers crossed) has remained very reliable. If I do have any issues I’ll be sure to run through your checklist, thanks for sharing!

    • Glad to know that you own a Toyota, Nate. Thank you for leaving a comment and your support. I hope my little knowledge can contribute to your knowledge too.


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