no spark?

If the security light is not flashing it is probably the crankshaft angle sensor. Here are instructions for you and the sensor location in the diagrams below. Check out the diagrams (below). Please let us know what happens.

initially my truck died while driving. i though it had just run out of gas. well i bled system and have gas going to injectors but have no spark at the coil. I've replaced coil and checked relays and fuses. even replaced camshaft sensor and distributor is in good working condition as well. so I'm at a loss as to why I'm not getting spam and engine not turning over

How are you checking for spark if the engine won't crank?

The fuel pressure at the injectors is misleading because the fuel pump will run for one second after turning on the ignition switch. That will get the pressure up in case it bled down overnight but it doesn't verify the pump is running during engine cranking.

Which engine do you have? Are we working on a failure to crank or a failure to start?

it cranks all day long. i have the 5.2 liter engine. old school spark plug and screwdriver method for checking for spark. have a voltmeter i used to make sure power is getting to coil. we are working on failure to start

First check for any diagnostic fault codes. Cycle the ignition switch three times from "off" to "run" within five seconds without cranking the engine, leave it in "run", then watch the numbers appear in the odometer display.

Next, measure the voltage at the ignition coil positive wire or any injector wire. Those are typically dark green / orange. You will see 12 volts there for one second after turning on the ignition switch. What's important is if that voltage comes back during cranking. If it does not, the most common suspect is the crankshaft position sensor. You may have better luck checking that with a test light. Most digital voltmeters don't respond fast enough to catch that one-second blip.

I've replaced the crankshaft sensor. when i cycled the ignition the odometer reads pdone. and the light flutters upon cranking

If the light is flashing you're on the switched side of the coil or injector but that still tells us the automatic shutdown relay is turning on. That means the camshaft position sensor and crankshaft position sensor are working, and that leaves an ignition system or fuel supply system problem. Listen by the gas tank too hear if the pump runs for one second when a helper turns on the ignition switch.

If you had the test light at the ignition coil and it was flashing, you should be getting spark. Try a squirt of starting fluid to see if you have a fuel pressure problem.

the light did not flash during cranking it stayed lit the entire time engine cranked

What did you mean by "and the light flutters upon cranking"? Where were you taking that measurement?

Did you listen for the hum of the fuel pump?

yes it makes a hum sound. checked coil wire plug. the green orange wire but light never turned off or even dimmed during cranking

Just so we're clear, on the dark green / orange wire, the test light should light up for one second after turning on the ignition switch, turn off, then turn on only during cranking. It must go off within about one second when you stop cranking. If that's what's happening, the Engine Computer is turning on the automatic shutdown (ASD) relay as it should. On the '90s models that would prove the crankshaft position sensor and camshaft position sensor are working. Both have to send signals to the computer to tell it the engine is rotating before it will turn on the ASD relay. That relay is what switches on the 12 volts for the injectors, ignition coil, alternator field, oxygen sensor heaters, and fuel pump or pump relay. If either sensor failed while driving, the engine would stall.

Beginning on some 2000 models one of those two sensors could fail while driving and the ASD relay would stay on and the engine would run on a backup strategy, but once the engine was stopped it would not restart. To verify that you need a scanner to view live data. Under the "Sensors" menu you would watch the cam and crank sensors during engine cranking. They will be listed as "present" or "no". If both are present you have an ignition system problem or a fuel supply problem. If either sensor is listed as "no", both the ignition and fuel supply systems will be dead.

Until we learn differently, we can assume both sensors are working since the ASD relay is turning on. With no spark that leaves the ignition coil, wires to it, and the Engine Computer. You already replaced the coil, and you measured 12 volts to it. Put your test light on the other small coil wire and see what happens during engine cranking. If it's on steady the computer is not switching it or there's a break in that wire.

No mechanic likes to throw a computer at a problem because it introduces too many new variables, and it rarely solves a problem like this, and before you do, you can use the scanner in "Actuator Test Mode", (ATM) to command the Engine Computer to fire the ignition coil. That will instantly tell you whether the circuit is working or if there's a problem in the computer.

Was that a new or used crank sensor you installed? Did it have a thick paper spacer stuck on the end, or a thin plastic rib molded in?

shuts down no spark no fuel throughs no codes 3 to 10 mins starts up goes till next time

Have the ASD checked.

thank you how do i test the ASD

Basically, you are checkng for continunity to see if the circuit is completed.

Electrical problem
1999 Dodge Ram V8 Two Wheel Drive Automatic

I have 99 dodge sport ram 5.9 with 12000 mi, it starts sometimes .but when i stop it don't won't to start. my fuel pump is coming on. i have spark at the coil. but no spark at the plugs. i let it set a long time and go to start it and it will start.

Hi:
Check to make sure the high tension wires are in good shape, the rotor is good (not corroded) and plug wires are good. Let me know what you find.

Joe

99 Dodge Ram 1500 5.9 Cranks good no spark or injector pulse, has new crank sensor & ign switch. No voltage to coil or distributor. What to test first?

scanfor codes and check fuel pressure first

we have no spark, no injector pulse and no communication with on board computer.

check your power and grounds to the pcm.

Roy

Look in your power distribution box there should be a 100amp main fuse see if its blown

any luck???

Roy

yes it was the ASD relay

No spark from coil.

For crank / no-starts, most commonly you're also missing injector pulses and the fuel pump, so don't waste a lot of valuable time in the ignition system. The first thing to do is read the diagnostic fault codes. Next, we want to know if the automatic shutdown, (ASD) relay is working. The easiest way to see if the circuit is working is to measure the voltage on the dark green / orange wire at the coil pack or any injector. I prefer to use a test light so I can see it from inside the truck.

You should see the 12 volts appear for one second when you turn on the ignition switch, then it will go back to 0 volts. That proves the the ASD relay is okay and the Engine Computer has control of it. You should also hear the hum of the fuel pump for that one second. What is important is if that 12 volts comes back during cranking. Most commonly for crank / no-starts, it will not, then you will have no injector pulses and no spark. About five percent of the time the 12 volts will come back during cranking. In that case you have a fuel supply or an ignition problem, but not both.

When the ASD relay doesn't turn back on during cranking, the two common suspects are the crankshaft position sensor and the camshaft position sensor. If one of those failed, you might have a diagnostic fault code to tell you which circuit to diagnose, but the absence of a fault code doesn't mean the sensors are working properly.

If you haven't read the fault codes yet, that should be the first step in the diagnosis, and that must be done before the battery is disconnected or run dead. Doing so will erase the codes, then that valuable information will be lost.

You can go here to see the code definitions:

https://www.2carpros.com/trouble_codes/obd2

or tell me the code numbers and I can interpret them for you.

Chrysler made reading the fault codes yourself real easy. Cycle the ignition switch from "off" to run" three times within five seconds without cranking the engine, leave it in "run", then watch the code numbers appear in the odometer display.

This drawing shows the location of the crankshaft position sensor. It is as would be seen from the front passenger seat. The camshaft position sensor is inside the distributor.