Skip the auto shop - Our mechanics make house calls

Q: Truck will crank, but engine won't start - 1973 Chevrolet K20

asked by on

The old battery in my car would not hold a charge, so I replaced it with a new one. After installing the new battery, the truck will crank, but the engine will not start. I held a plug wire next to ground to test for spark, but there was nothing. I also used the same technique to test the coil wire - nothing. Next, I tested for voltage across the input wires to the coil. When the ignition engaged, there were only 4 volts. Next, at the ignition fuse, in the fuse panel, I tested for voltage and saw 12 volts. I know that from the starter solenoid is the only other direction that the voltage comes from. When I tested there, it was 12 volts going into the solenoid, however only 4 were coming back to the coil. My truck’s starter is a new one that I installed several months ago. Next to the distributor is a small capacitor-looking part in the same bracket with the coil. I don't know if this is a resistor or a capacitor. There is only one connection that goes to the coil’s back side connection. I have been researching for wiring diagrams but so far haven't found any. Could you please give me whatever help you can for these problems?

A: Hello there, thanks for writing in. The wir...

Hello there, thanks for writing in. The wiring diagram for the ignition system of your vehicle is pretty simple. Power flows from the ignition switch to the coil. When the engine is cranked, the points open and close to create voltage in the coil secondary windings. This creates the high voltage needed to fire the spark plugs, which is sent to the distributor.

If there is no spark, suspect a faulty coil, coil wire, cap rotor, points or distributor. The wiring between the ignition switch and coil could also be bad. A faulty starter will not prevent the engine from getting spark.

It sounds like you've already spent a lot of time on this issue; if you'd like further assistance, consider having one of our certified automotive technicians come to your home or office to diagnose and repair your vehicle properly.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%

Get a quote

What others are asking

Q: Car doesn't recognize the key when it's inserted

There are several common possible issues. Low battery voltage can cause this type of situation to occur. Another possibility is a problem in the drive authorization system. The key itself is also something to consider. The drive authorization system needs...

Q: Engine not cranking.

The starter may be defective or the ignition switch may be the issue. The system would need to be checked by a qualified mechanic to trace the problem down.

Q: My mustang keeps dying.

Hey there. There is a fuse in the fuse junction box within the engine fuse box that needs to be checked. It is a 20amp fuse. There are two fuse link wires that go from junction box to the alternator....

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...