Check gauges light is on car will not start?

LUKEFAIN02

MEMBER
2000 DODGE DURANGO
5.9L
V8
4WD
AUTOMATIC
215,000 MILES

Check gauge light comes on and the car won't stay on unless I rev it. I don't think there's and knocking or anything coming from the engine. The battery is drained I believe because it won't start without a jump and when it does start, I have to rev it about 2k RPMs. Any idea on what might be going on if I did have a knock or something wrong with the block wouldn't the check engine light come on? The oils are fine, there's no oil in the coolant tank, not that I can see. Not blowing any smoke unless I start it up from sitting over night or a few hours. But the smoke comes from the exhaust. Car ran fine the day before although Every time I coasted down a hill and not pressed the gas the engine would cut off for some reason would appreciate any help pretty broke so can't afford any parts hopefully getting a job soon this is my first car and would like to keep it.

2 Replies

CARADIODOC

MECHANIC
33,744 POSTS

Don't worry about the stalling for now. That has an extremely easy solution once the dead battery problem is solved. It sounds like the charging system is not keeping the battery charged. The "Check Gauges" light is telling you to look at the "Volts" gauge on the dash.

You can do the first part of the system test with an inexpensive digital voltmeter. Harbor Freight Tools has a perfectly fine one for $7.00. You can find them at Walmart and any hardware store too. This article:

https://www.2carpros.com/articles/how-to-use-a-voltmeter

shows how to use the meter, but they're using one with "auto-ranging". That's an expensive feature you don't need. If you need help setting up your meter, I can help with that.

Start by measuring the battery's voltage with the engine not running. A good, fully-charged battery will read very close to 12.6 volts. If it's good but fully-discharged, it will be closer to 12.2 volts. It should be charged at a slow rate for a few hours with a portable charger.

Next, measure it again with the engine running. If you need to use jumper cables and another car to get yours started, the cables must be removed during any testing, otherwise you'll be testing the wrong car. Now it should be between 13.75 and 14.75 volts. If it stays close to 12.6 volts or less, the alternator is not working. If that is the case, you'll need to measure the voltages on the two smaller terminals on the back of the alternator, but that has to be done with the engine running.

Let me know what you find with those two voltages.