How To Test A Does Not Crank Condition -Case Study (GM 3.8L)

Testing a ‘does not crank’ problem can sometimes be a challenge since so many things can can cause it.

With this Case Study, I'll explain some of the basic testing/troubleshooting steps that are usually done to test for a DOES NOT CRANK Condition (this is a condition in which the engine does not turn over). You should be able to see that:

  1. These tests do not require expensive tools or testing equipment.
  2. That they are very easy to perform.
  3. These testing guidelines apply to any vehicle you may be driving or repairing.
  4. The different causes of a DOES NOT CRANK Condition.
  5. How to test a BAD STARTER MOTOR and by extension how to eliminate a BAD BATTERY as the cause of the problem.

Although the test steps in this case study were done on a 3.8L GM vehicle, the basic troubleshooting applies to any type of vehicle.

Puedes encontrar este tutorial el Español aquí: Pruebas Cuando No Arranca -Estudio de Caso (GM 3.8L) (en: autotecnico-online.com).

Alright, lets get started...Here's how it all happened:

Is It The Battery Or The Starter Motor?

It's bad enough you're having to run around all day long doing errands (on a cold day to top it off) and in the middle of it all; the car dies on you as you're driving down the road, yeah, the icing on the cake! Lucky you, you were able to coast into a parking lot where you try to get the car to start but it won't cooperate.

If this were to really happen to you, I'd say, the first thing to go thru' your mind would be that the starter went bad. Well, I take that back... maybe that wouldn't be the first thing, 'cause I'm sure (if I were in your situation) there would be some other very choice thoughts/words come in and out first.

Well, getting over the initial ‘Why me?’ frustration, you ask yourself- Is it the starter or is it the battery.

Not knowing what's going on, you finally decide it has to be the battery. After asking a thousand people to help you to jump-start the car you finally find a Good Samaritan to help you. After thirty minutes of trying to jump-start the car, it still won't start. The engine will not turn over. Why can't this stuff happen on a beautiful and very sunny 70 degree (°F) day?

Out comes the cellphone and after what seems like an eternity, finally the tow truck arrives... kinda' like our friendly boys in blue, never around when you really need them (but always there to man a speed trap).

This is exactly what happened to a customer, of the auto repair shop where I work, involving his 1998 Oldsmobile Intrigue. This Case Study has a twist to it, since the problem was neither the battery nor the starter motor.

There are many things that can cause a NO CRANK - NO START CONDITION. In this article I'll tell you what I did to narrow down the search for the ‘truth’ and arrive at the correct conclusion. The test method I'll be describing is simple and can be applied to the majority (if not all) of cars on the road today. So read on my friend....

A NO CRANK-NO START CONDITION is usually one of the easiest problems to test and solve and with this case study I'll show just why this is. Not to mention that having the right info (no baloney) makes a difference in testing the starter motor. Lets read how it all happened.

But before I go on, let me just say that the biggest reason (that these are the easiest problems to solve) is that there's a specific flow of: step 1 test this, step 2 test that, and so on and so forth that are performed to arrive at the correct conclusion. So, keep reading and I'll show you how it works: