Q: Car parked for 1 month has dead battery

asked by on

After having to park my car for a month, it wouldn't start due to the dead battery. It is a 4 cylinder engine. After charging it, we found a vacuum leak. Fixed the leak, but after just 2 miles of driving, it lost power. My friend (who works in an auto repair shop) thought the ignition might be the problem, so he replaced it. Car still wouldn't start and only tests at 1 volt. Next, he took out the distributor, tested it and it works fine. Now, he thinks the problem might be the crank position sensor or the rpm speed sensor. But he doesn’t really know what the problem is. To continue - now the battery is fully charged and he says the problem isn’t the alternator, which he checked. When I asked him about the 1 volt reading, he said it was the crank position sensor/ rpm speed sensor. He has just about checked everything. My car had stalled when I came to a complete stop and that’s when it had lost power. This same thing happened also when the rotor button was bad on the distributor, but my friend also checked that and said that is good. Can you tell me what we should look for that will fix this problem?

The engine computer definitely needs to see engine RPM in order to power the coil. Between the ignition coils and the engine computer is an ignition coil power output stage unit which is supplied power from the engine computer. The power into this unit can be checked at the three pin connector at the unit. All 3 wires will measure battery voltage with the key on and the plug disconnected when measured with a voltmeter between the connector and ground.

A low voltage reading indicates a problem in either the engine computer or the wiring. While a battery voltage reading at the connector with a 1 volt reading at the coil indicates an issue in the ignition coil final stage unit or the wiring from the unit to the coil. You may want to enlist the help of a mechanic, such as one from YourMechanic, who will have equipment and expertise needed to diagnose the no start issue.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1,000 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!
  1. Home
  2. Questions
  3. Car parked for 1 month has dead battery

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Car starting roughly

If you are hearing a grinding noise for a few seconds on engine start up, the timing chain tensioners are to blame. There are two chain tensioners, however, if one is bad, both are replaced. It is a rather large...

Q: Engine shuts down suddenly, battery red warning light on

I would say the tensioner was overlooked on the last repair and the oil pressure switch may have been damaged in the repair process. I would recommend having the repairs done, but ask for the old parts to see if...

Q: can cup hands over carburetor when its running and it will not stall

Hello and thank you for your question. Yes, you are right but only if you have completely shut off the air intake at that point. Not sure that cupping your hands will do it but surely you can be the...

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 are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...
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...